diff --git a/tests/wpt/metadata-layout-2020/FileAPI/url/url-in-tags-revoke.window.js.ini b/tests/wpt/metadata-layout-2020/FileAPI/url/url-in-tags-revoke.window.js.ini
index 68bf21994e8..62c2d998e8f 100644
--- a/tests/wpt/metadata-layout-2020/FileAPI/url/url-in-tags-revoke.window.js.ini
+++ b/tests/wpt/metadata-layout-2020/FileAPI/url/url-in-tags-revoke.window.js.ini
@@ -4,7 +4,7 @@
     expected: TIMEOUT
 
   [Opening a blob URL in a new window immediately before revoking it works.]
-    expected: TIMEOUT
+    expected: FAIL
 
   [Fetching a blob URL immediately before revoking it works in an iframe.]
     expected: FAIL
diff --git a/tests/wpt/metadata-layout-2020/css/CSS2/floats/hit-test-floats-002.html.ini b/tests/wpt/metadata-layout-2020/css/CSS2/floats/hit-test-floats-002.html.ini
new file mode 100644
index 00000000000..968f62a2553
--- /dev/null
+++ b/tests/wpt/metadata-layout-2020/css/CSS2/floats/hit-test-floats-002.html.ini
@@ -0,0 +1,3 @@
+[hit-test-floats-002.html]
+  [Hit test float]
+    expected: FAIL
diff --git a/tests/wpt/metadata-layout-2020/css/CSS2/normal-flow/block-in-inline-hittest-002.html.ini b/tests/wpt/metadata-layout-2020/css/CSS2/normal-flow/block-in-inline-hittest-002.html.ini
index 51432362d66..ee34bc91078 100644
--- a/tests/wpt/metadata-layout-2020/css/CSS2/normal-flow/block-in-inline-hittest-002.html.ini
+++ b/tests/wpt/metadata-layout-2020/css/CSS2/normal-flow/block-in-inline-hittest-002.html.ini
@@ -1,3 +1,6 @@
 [block-in-inline-hittest-002.html]
   [elementsFromPoint]
     expected: FAIL
+
+  [elementFromPoint]
+    expected: FAIL
diff --git a/tests/wpt/metadata-layout-2020/css/CSS2/normal-flow/block-in-inline-hittest-float-002.html.ini b/tests/wpt/metadata-layout-2020/css/CSS2/normal-flow/block-in-inline-hittest-float-002.html.ini
deleted file mode 100644
index 3e5096beef3..00000000000
--- a/tests/wpt/metadata-layout-2020/css/CSS2/normal-flow/block-in-inline-hittest-float-002.html.ini
+++ /dev/null
@@ -1,3 +0,0 @@
-[block-in-inline-hittest-float-002.html]
-  [block-in-inline-hittest-float-002]
-    expected: FAIL
diff --git a/tests/wpt/metadata-layout-2020/css/css-animations/missing-values-first-keyframe.html.ini b/tests/wpt/metadata-layout-2020/css/css-animations/missing-values-first-keyframe.html.ini
new file mode 100644
index 00000000000..303457f9ba4
--- /dev/null
+++ b/tests/wpt/metadata-layout-2020/css/css-animations/missing-values-first-keyframe.html.ini
@@ -0,0 +1,3 @@
+[missing-values-first-keyframe.html]
+  [Missing property values in the first keyframe are correctly interpolated from a neutral keyframe value]
+    expected: FAIL
diff --git a/tests/wpt/metadata-layout-2020/css/css-animations/missing-values-last-keyframe.html.ini b/tests/wpt/metadata-layout-2020/css/css-animations/missing-values-last-keyframe.html.ini
new file mode 100644
index 00000000000..855cf2cc9ce
--- /dev/null
+++ b/tests/wpt/metadata-layout-2020/css/css-animations/missing-values-last-keyframe.html.ini
@@ -0,0 +1,3 @@
+[missing-values-last-keyframe.html]
+  [Missing property values in the last keyframe are correctly interpolated from a neutral keyframe value]
+    expected: FAIL
diff --git a/tests/wpt/metadata-layout-2020/css/css-flexbox/abspos/position-absolute-013.html.ini b/tests/wpt/metadata-layout-2020/css/css-flexbox/abspos/position-absolute-013.html.ini
index d4f9786638e..f3d5a1904d9 100644
--- a/tests/wpt/metadata-layout-2020/css/css-flexbox/abspos/position-absolute-013.html.ini
+++ b/tests/wpt/metadata-layout-2020/css/css-flexbox/abspos/position-absolute-013.html.ini
@@ -1,4 +1,5 @@
 [position-absolute-013.html]
+  expected: TIMEOUT
   [.flexbox 309]
     expected: FAIL
 
diff --git a/tests/wpt/metadata-layout-2020/css/css-fonts/variations/at-font-face-font-matching.html.ini b/tests/wpt/metadata-layout-2020/css/css-fonts/variations/at-font-face-font-matching.html.ini
index dbe71f47afd..6de492add85 100644
--- a/tests/wpt/metadata-layout-2020/css/css-fonts/variations/at-font-face-font-matching.html.ini
+++ b/tests/wpt/metadata-layout-2020/css/css-fonts/variations/at-font-face-font-matching.html.ini
@@ -319,3 +319,9 @@
 
   [Matching font-style: 'italic' should prefer 'oblique 30deg 60deg' over 'oblique 40deg 50deg']
     expected: FAIL
+
+  [Matching font-weight: '501' should prefer '503 520' over '500']
+    expected: FAIL
+
+  [Matching font-style: 'oblique -10deg' should prefer 'oblique -50deg -40deg' over 'italic']
+    expected: FAIL
diff --git a/tests/wpt/metadata-layout-2020/css/css-transitions/properties-value-001.html.ini b/tests/wpt/metadata-layout-2020/css/css-transitions/properties-value-001.html.ini
index c4daffd168f..3094ea29f3c 100644
--- a/tests/wpt/metadata-layout-2020/css/css-transitions/properties-value-001.html.ini
+++ b/tests/wpt/metadata-layout-2020/css/css-transitions/properties-value-001.html.ini
@@ -52,3 +52,153 @@
 
   [background-position length(px) / events]
     expected: FAIL
+
+  [padding-bottom length(ex) / values]
+    expected: FAIL
+
+  [padding-bottom length(mm) / values]
+    expected: FAIL
+
+  [padding-bottom length(cm) / values]
+    expected: FAIL
+
+  [padding-bottom length(in) / values]
+    expected: FAIL
+
+  [padding-left length(pt) / values]
+    expected: FAIL
+
+  [padding-left length(pc) / values]
+    expected: FAIL
+
+  [padding-left length(px) / values]
+    expected: FAIL
+
+  [padding-left length(em) / values]
+    expected: FAIL
+
+  [padding-left length(ex) / values]
+    expected: FAIL
+
+  [padding-left length(mm) / values]
+    expected: FAIL
+
+  [padding-left length(cm) / values]
+    expected: FAIL
+
+  [padding-left length(in) / values]
+    expected: FAIL
+
+  [padding-right length(pt) / values]
+    expected: FAIL
+
+  [padding-right length(pc) / values]
+    expected: FAIL
+
+  [padding-right length(px) / values]
+    expected: FAIL
+
+  [padding-right length(em) / values]
+    expected: FAIL
+
+  [padding-right length(ex) / values]
+    expected: FAIL
+
+  [padding-right length(mm) / values]
+    expected: FAIL
+
+  [padding-right length(cm) / values]
+    expected: FAIL
+
+  [padding-right length(in) / values]
+    expected: FAIL
+
+  [padding-top length(pt) / values]
+    expected: FAIL
+
+  [padding-top length(pc) / values]
+    expected: FAIL
+
+  [padding-top length(px) / values]
+    expected: FAIL
+
+  [padding-top length(em) / values]
+    expected: FAIL
+
+  [padding-top length(ex) / values]
+    expected: FAIL
+
+  [padding-top length(mm) / values]
+    expected: FAIL
+
+  [padding-top length(cm) / values]
+    expected: FAIL
+
+  [padding-top length(in) / values]
+    expected: FAIL
+
+  [margin-bottom length(pt) / values]
+    expected: FAIL
+
+  [margin-bottom length(pc) / values]
+    expected: FAIL
+
+  [margin-bottom length(px) / values]
+    expected: FAIL
+
+  [margin-bottom length(em) / values]
+    expected: FAIL
+
+  [margin-bottom length(ex) / values]
+    expected: FAIL
+
+  [margin-bottom length(mm) / values]
+    expected: FAIL
+
+  [margin-bottom length(cm) / values]
+    expected: FAIL
+
+  [margin-bottom length(in) / values]
+    expected: FAIL
+
+  [margin-left length(pt) / values]
+    expected: FAIL
+
+  [margin-left length(pc) / values]
+    expected: FAIL
+
+  [margin-left length(px) / values]
+    expected: FAIL
+
+  [margin-left length(em) / values]
+    expected: FAIL
+
+  [margin-left length(ex) / values]
+    expected: FAIL
+
+  [margin-left length(mm) / values]
+    expected: FAIL
+
+  [margin-left length(cm) / values]
+    expected: FAIL
+
+  [margin-left length(in) / values]
+    expected: FAIL
+
+  [margin-right length(pt) / values]
+    expected: FAIL
+
+  [margin-right length(pc) / values]
+    expected: FAIL
+
+  [margin-right length(px) / values]
+    expected: FAIL
+
+  [margin-right length(em) / values]
+    expected: FAIL
+
+  [margin-right length(ex) / values]
+    expected: FAIL
+
+  [margin-right length(mm) / values]
+    expected: FAIL
diff --git a/tests/wpt/metadata-layout-2020/css/css-transitions/properties-value-inherit-001.html.ini b/tests/wpt/metadata-layout-2020/css/css-transitions/properties-value-inherit-001.html.ini
index 03f4e0ef301..998682c8a35 100644
--- a/tests/wpt/metadata-layout-2020/css/css-transitions/properties-value-inherit-001.html.ini
+++ b/tests/wpt/metadata-layout-2020/css/css-transitions/properties-value-inherit-001.html.ini
@@ -205,3 +205,303 @@
 
   [margin-right length(mm) / events]
     expected: FAIL
+
+  [margin-right length(cm) / events]
+    expected: FAIL
+
+  [margin-right length(in) / events]
+    expected: FAIL
+
+  [margin-top length(pt) / events]
+    expected: FAIL
+
+  [margin-top length(pc) / events]
+    expected: FAIL
+
+  [margin-top length(px) / events]
+    expected: FAIL
+
+  [margin-top length(em) / events]
+    expected: FAIL
+
+  [margin-top length(ex) / events]
+    expected: FAIL
+
+  [margin-top length(mm) / events]
+    expected: FAIL
+
+  [margin-top length(cm) / events]
+    expected: FAIL
+
+  [margin-top length(in) / events]
+    expected: FAIL
+
+  [height length(pt) / events]
+    expected: FAIL
+
+  [height length(pc) / events]
+    expected: FAIL
+
+  [height length(px) / events]
+    expected: FAIL
+
+  [height length(em) / events]
+    expected: FAIL
+
+  [height length(ex) / events]
+    expected: FAIL
+
+  [height length(mm) / events]
+    expected: FAIL
+
+  [height length(cm) / events]
+    expected: FAIL
+
+  [height length(in) / events]
+    expected: FAIL
+
+  [height percentage(%) / events]
+    expected: FAIL
+
+  [width length(pt) / events]
+    expected: FAIL
+
+  [width length(pc) / events]
+    expected: FAIL
+
+  [width length(px) / events]
+    expected: FAIL
+
+  [width length(em) / events]
+    expected: FAIL
+
+  [width length(ex) / events]
+    expected: FAIL
+
+  [width length(mm) / events]
+    expected: FAIL
+
+  [width length(cm) / events]
+    expected: FAIL
+
+  [width length(in) / events]
+    expected: FAIL
+
+  [width percentage(%) / events]
+    expected: FAIL
+
+  [min-height length(pt) / events]
+    expected: FAIL
+
+  [min-height length(pc) / events]
+    expected: FAIL
+
+  [min-height length(px) / events]
+    expected: FAIL
+
+  [min-height length(em) / events]
+    expected: FAIL
+
+  [min-height length(ex) / events]
+    expected: FAIL
+
+  [min-height length(mm) / events]
+    expected: FAIL
+
+  [min-height length(cm) / events]
+    expected: FAIL
+
+  [min-height length(in) / events]
+    expected: FAIL
+
+  [min-height percentage(%) / events]
+    expected: FAIL
+
+  [min-width length(pt) / events]
+    expected: FAIL
+
+  [min-width length(pc) / events]
+    expected: FAIL
+
+  [min-width length(px) / events]
+    expected: FAIL
+
+  [min-width length(em) / events]
+    expected: FAIL
+
+  [min-width length(ex) / events]
+    expected: FAIL
+
+  [min-width length(mm) / events]
+    expected: FAIL
+
+  [min-width length(cm) / events]
+    expected: FAIL
+
+  [min-width length(in) / events]
+    expected: FAIL
+
+  [min-width percentage(%) / events]
+    expected: FAIL
+
+  [max-height length(pt) / events]
+    expected: FAIL
+
+  [max-height length(pc) / events]
+    expected: FAIL
+
+  [max-height length(px) / events]
+    expected: FAIL
+
+  [max-height length(em) / events]
+    expected: FAIL
+
+  [max-height length(ex) / events]
+    expected: FAIL
+
+  [max-height length(mm) / events]
+    expected: FAIL
+
+  [max-height length(cm) / events]
+    expected: FAIL
+
+  [max-height length(in) / events]
+    expected: FAIL
+
+  [max-height percentage(%) / events]
+    expected: FAIL
+
+  [max-width length(pt) / events]
+    expected: FAIL
+
+  [max-width length(pc) / events]
+    expected: FAIL
+
+  [max-width length(px) / events]
+    expected: FAIL
+
+  [max-width length(em) / events]
+    expected: FAIL
+
+  [max-width length(ex) / events]
+    expected: FAIL
+
+  [max-width length(mm) / events]
+    expected: FAIL
+
+  [max-width length(cm) / events]
+    expected: FAIL
+
+  [max-width length(in) / events]
+    expected: FAIL
+
+  [max-width percentage(%) / events]
+    expected: FAIL
+
+  [top length(pt) / events]
+    expected: FAIL
+
+  [top length(pc) / events]
+    expected: FAIL
+
+  [top length(px) / events]
+    expected: FAIL
+
+  [top length(em) / events]
+    expected: FAIL
+
+  [top length(ex) / events]
+    expected: FAIL
+
+  [top length(mm) / events]
+    expected: FAIL
+
+  [top length(cm) / events]
+    expected: FAIL
+
+  [top length(in) / events]
+    expected: FAIL
+
+  [top percentage(%) / events]
+    expected: FAIL
+
+  [right length(pt) / events]
+    expected: FAIL
+
+  [right length(pc) / events]
+    expected: FAIL
+
+  [right length(px) / events]
+    expected: FAIL
+
+  [right length(em) / events]
+    expected: FAIL
+
+  [right length(ex) / events]
+    expected: FAIL
+
+  [right length(mm) / events]
+    expected: FAIL
+
+  [right length(cm) / events]
+    expected: FAIL
+
+  [right length(in) / events]
+    expected: FAIL
+
+  [right percentage(%) / events]
+    expected: FAIL
+
+  [bottom length(pt) / events]
+    expected: FAIL
+
+  [bottom length(pc) / events]
+    expected: FAIL
+
+  [bottom length(px) / events]
+    expected: FAIL
+
+  [bottom length(em) / events]
+    expected: FAIL
+
+  [bottom length(ex) / events]
+    expected: FAIL
+
+  [bottom length(mm) / events]
+    expected: FAIL
+
+  [bottom length(cm) / events]
+    expected: FAIL
+
+  [bottom length(in) / events]
+    expected: FAIL
+
+  [bottom percentage(%) / events]
+    expected: FAIL
+
+  [left length(pt) / events]
+    expected: FAIL
+
+  [left length(pc) / events]
+    expected: FAIL
+
+  [left length(px) / events]
+    expected: FAIL
+
+  [left length(em) / events]
+    expected: FAIL
+
+  [left length(ex) / events]
+    expected: FAIL
+
+  [left length(mm) / events]
+    expected: FAIL
+
+  [left length(cm) / events]
+    expected: FAIL
+
+  [left length(in) / events]
+    expected: FAIL
+
+  [left percentage(%) / events]
+    expected: FAIL
diff --git a/tests/wpt/metadata-layout-2020/css/css-transitions/properties-value-inherit-002.html.ini b/tests/wpt/metadata-layout-2020/css/css-transitions/properties-value-inherit-002.html.ini
index 242ba44bbca..793afafa0e8 100644
--- a/tests/wpt/metadata-layout-2020/css/css-transitions/properties-value-inherit-002.html.ini
+++ b/tests/wpt/metadata-layout-2020/css/css-transitions/properties-value-inherit-002.html.ini
@@ -52,3 +52,276 @@
 
   [background-position length(px) / events]
     expected: FAIL
+
+  [background-color color(rgba) / values]
+    expected: FAIL
+
+  [border-top-width length(pt) / values]
+    expected: FAIL
+
+  [border-top-width length(pc) / values]
+    expected: FAIL
+
+  [border-top-width length(px) / values]
+    expected: FAIL
+
+  [border-top-width length(em) / values]
+    expected: FAIL
+
+  [border-top-width length(ex) / values]
+    expected: FAIL
+
+  [border-top-width length(mm) / values]
+    expected: FAIL
+
+  [border-top-width length(cm) / values]
+    expected: FAIL
+
+  [border-top-width length(in) / values]
+    expected: FAIL
+
+  [border-right-width length(pt) / values]
+    expected: FAIL
+
+  [border-right-width length(pc) / values]
+    expected: FAIL
+
+  [border-right-width length(px) / values]
+    expected: FAIL
+
+  [border-right-width length(em) / values]
+    expected: FAIL
+
+  [border-right-width length(ex) / values]
+    expected: FAIL
+
+  [border-right-width length(mm) / values]
+    expected: FAIL
+
+  [border-right-width length(cm) / values]
+    expected: FAIL
+
+  [border-right-width length(in) / values]
+    expected: FAIL
+
+  [border-bottom-width length(pt) / values]
+    expected: FAIL
+
+  [border-bottom-width length(pc) / values]
+    expected: FAIL
+
+  [border-bottom-width length(px) / values]
+    expected: FAIL
+
+  [border-bottom-width length(em) / values]
+    expected: FAIL
+
+  [border-bottom-width length(ex) / values]
+    expected: FAIL
+
+  [border-bottom-width length(mm) / values]
+    expected: FAIL
+
+  [border-bottom-width length(cm) / values]
+    expected: FAIL
+
+  [border-bottom-width length(in) / values]
+    expected: FAIL
+
+  [border-left-width length(pt) / values]
+    expected: FAIL
+
+  [border-left-width length(pc) / values]
+    expected: FAIL
+
+  [border-left-width length(px) / values]
+    expected: FAIL
+
+  [border-left-width length(em) / values]
+    expected: FAIL
+
+  [border-left-width length(ex) / values]
+    expected: FAIL
+
+  [border-left-width length(mm) / values]
+    expected: FAIL
+
+  [border-left-width length(cm) / values]
+    expected: FAIL
+
+  [border-left-width length(in) / values]
+    expected: FAIL
+
+  [border-top-color color(rgba) / values]
+    expected: FAIL
+
+  [border-right-color color(rgba) / values]
+    expected: FAIL
+
+  [border-bottom-color color(rgba) / values]
+    expected: FAIL
+
+  [border-left-color color(rgba) / values]
+    expected: FAIL
+
+  [padding-bottom length(pt) / values]
+    expected: FAIL
+
+  [padding-bottom length(pc) / values]
+    expected: FAIL
+
+  [padding-bottom length(px) / values]
+    expected: FAIL
+
+  [padding-bottom length(em) / values]
+    expected: FAIL
+
+  [color color(rgba) / values]
+    expected: FAIL
+
+  [font-size length(pt) / values]
+    expected: FAIL
+
+  [font-size length(pc) / values]
+    expected: FAIL
+
+  [font-size length(px) / values]
+    expected: FAIL
+
+  [font-size length(em) / values]
+    expected: FAIL
+
+  [font-size length(ex) / values]
+    expected: FAIL
+
+  [font-size length(mm) / values]
+    expected: FAIL
+
+  [font-size length(cm) / values]
+    expected: FAIL
+
+  [font-size length(in) / values]
+    expected: FAIL
+
+  [font-size percentage(%) / values]
+    expected: FAIL
+
+  [font-weight font-weight(keyword) / values]
+    expected: FAIL
+
+  [font-weight font-weight(numeric) / values]
+    expected: FAIL
+
+  [line-height number(integer) / values]
+    expected: FAIL
+
+  [line-height number(decimal) / values]
+    expected: FAIL
+
+  [line-height length(pt) / values]
+    expected: FAIL
+
+  [line-height length(pc) / values]
+    expected: FAIL
+
+  [line-height length(px) / values]
+    expected: FAIL
+
+  [line-height length(em) / values]
+    expected: FAIL
+
+  [line-height length(ex) / values]
+    expected: FAIL
+
+  [line-height length(mm) / values]
+    expected: FAIL
+
+  [line-height length(cm) / values]
+    expected: FAIL
+
+  [line-height length(in) / values]
+    expected: FAIL
+
+  [line-height percentage(%) / values]
+    expected: FAIL
+
+  [letter-spacing length(pt) / values]
+    expected: FAIL
+
+  [letter-spacing length(pc) / values]
+    expected: FAIL
+
+  [letter-spacing length(px) / values]
+    expected: FAIL
+
+  [letter-spacing length(em) / values]
+    expected: FAIL
+
+  [letter-spacing length(ex) / values]
+    expected: FAIL
+
+  [letter-spacing length(mm) / values]
+    expected: FAIL
+
+  [letter-spacing length(cm) / values]
+    expected: FAIL
+
+  [letter-spacing length(in) / values]
+    expected: FAIL
+
+  [word-spacing length(pt) / values]
+    expected: FAIL
+
+  [word-spacing length(pc) / values]
+    expected: FAIL
+
+  [word-spacing length(px) / values]
+    expected: FAIL
+
+  [word-spacing length(em) / values]
+    expected: FAIL
+
+  [word-spacing length(ex) / values]
+    expected: FAIL
+
+  [word-spacing length(mm) / values]
+    expected: FAIL
+
+  [word-spacing length(cm) / values]
+    expected: FAIL
+
+  [word-spacing length(in) / values]
+    expected: FAIL
+
+  [word-spacing percentage(%) / values]
+    expected: FAIL
+
+  [text-indent length(pt) / values]
+    expected: FAIL
+
+  [text-indent length(pc) / values]
+    expected: FAIL
+
+  [text-indent length(px) / values]
+    expected: FAIL
+
+  [text-indent length(em) / values]
+    expected: FAIL
+
+  [text-indent length(ex) / values]
+    expected: FAIL
+
+  [text-indent length(mm) / values]
+    expected: FAIL
+
+  [text-indent length(cm) / values]
+    expected: FAIL
+
+  [text-indent length(in) / values]
+    expected: FAIL
+
+  [text-indent percentage(%) / values]
+    expected: FAIL
+
+  [text-shadow shadow(shadow) / values]
+    expected: FAIL
diff --git a/tests/wpt/metadata-layout-2020/css/css-transitions/pseudo-elements-001.html.ini b/tests/wpt/metadata-layout-2020/css/css-transitions/pseudo-elements-001.html.ini
index f7867715155..27fb29a8075 100644
--- a/tests/wpt/metadata-layout-2020/css/css-transitions/pseudo-elements-001.html.ini
+++ b/tests/wpt/metadata-layout-2020/css/css-transitions/pseudo-elements-001.html.ini
@@ -4,9 +4,3 @@
 
   [transition padding-left on :after / values]
     expected: FAIL
-
-  [transition padding-left on :before, changing content / values]
-    expected: FAIL
-
-  [transition padding-left on :after, changing content / values]
-    expected: FAIL
diff --git a/tests/wpt/metadata-layout-2020/css/cssom-view/MediaQueryList-addListener-handleEvent.html.ini b/tests/wpt/metadata-layout-2020/css/cssom-view/MediaQueryList-addListener-handleEvent.html.ini
index 037d7e0f951..2869eb8616e 100644
--- a/tests/wpt/metadata-layout-2020/css/cssom-view/MediaQueryList-addListener-handleEvent.html.ini
+++ b/tests/wpt/metadata-layout-2020/css/cssom-view/MediaQueryList-addListener-handleEvent.html.ini
@@ -4,3 +4,6 @@
 
   [throws if handleEvent is thruthy and not callable]
     expected: FAIL
+
+  [calls handleEvent method of event listener]
+    expected: FAIL
diff --git a/tests/wpt/metadata-layout-2020/css/cssom-view/elementFromPoint-dynamic-anon-box.html.ini b/tests/wpt/metadata-layout-2020/css/cssom-view/elementFromPoint-dynamic-anon-box.html.ini
new file mode 100644
index 00000000000..cf67b5d03dd
--- /dev/null
+++ b/tests/wpt/metadata-layout-2020/css/cssom-view/elementFromPoint-dynamic-anon-box.html.ini
@@ -0,0 +1,3 @@
+[elementFromPoint-dynamic-anon-box.html]
+  [Link should be clickable after hiding a scrollbox with an anonymous table inside]
+    expected: FAIL
diff --git a/tests/wpt/metadata-layout-2020/css/cssom-view/elementsFromPoint-invalid-cases.html.ini b/tests/wpt/metadata-layout-2020/css/cssom-view/elementsFromPoint-invalid-cases.html.ini
deleted file mode 100644
index a3496a40d07..00000000000
--- a/tests/wpt/metadata-layout-2020/css/cssom-view/elementsFromPoint-invalid-cases.html.ini
+++ /dev/null
@@ -1,3 +0,0 @@
-[elementsFromPoint-invalid-cases.html]
-  [The root element is the last element returned for otherwise empty queries within the viewport]
-    expected: FAIL
diff --git a/tests/wpt/metadata-layout-2020/css/cssom/CSSFontFeatureValuesRule.html.ini b/tests/wpt/metadata-layout-2020/css/cssom/CSSFontFeatureValuesRule.html.ini
index 601430b639c..e55d4bd51a2 100644
--- a/tests/wpt/metadata-layout-2020/css/cssom/CSSFontFeatureValuesRule.html.ini
+++ b/tests/wpt/metadata-layout-2020/css/cssom/CSSFontFeatureValuesRule.html.ini
@@ -19,3 +19,6 @@
 
   [Clearing all entries is possible.]
     expected: FAIL
+
+  [Multiple rules for the same family are kept separate in CSSOM.]
+    expected: FAIL
diff --git a/tests/wpt/metadata-layout-2020/fetch/content-length/parsing.window.js.ini b/tests/wpt/metadata-layout-2020/fetch/content-length/parsing.window.js.ini
index 3285a4f15ac..fc21a631bdd 100644
--- a/tests/wpt/metadata-layout-2020/fetch/content-length/parsing.window.js.ini
+++ b/tests/wpt/metadata-layout-2020/fetch/content-length/parsing.window.js.ini
@@ -76,3 +76,6 @@
 
   [Input: "Content-Length: ". Expected: 42.]
     expected: FAIL
+
+  [Input: "Content-Length: 30". Expected: 30.]
+    expected: FAIL
diff --git a/tests/wpt/metadata-layout-2020/fetch/content-type/response.window.js.ini b/tests/wpt/metadata-layout-2020/fetch/content-type/response.window.js.ini
index 8edde75f4d0..71592813e08 100644
--- a/tests/wpt/metadata-layout-2020/fetch/content-type/response.window.js.ini
+++ b/tests/wpt/metadata-layout-2020/fetch/content-type/response.window.js.ini
@@ -308,3 +308,6 @@
 
   [Response: combined response Content-Type: text/html;" \\" text/plain ";charset=GBK]
     expected: NOTRUN
+
+  [<iframe>: combined response Content-Type: text/html;charset=gbk text/plain text/html]
+    expected: FAIL
diff --git a/tests/wpt/metadata-layout-2020/fetch/metadata/generated/css-images.sub.tentative.html.ini b/tests/wpt/metadata-layout-2020/fetch/metadata/generated/css-images.sub.tentative.html.ini
index f9de5391ad6..9749a4fccd5 100644
--- a/tests/wpt/metadata-layout-2020/fetch/metadata/generated/css-images.sub.tentative.html.ini
+++ b/tests/wpt/metadata-layout-2020/fetch/metadata/generated/css-images.sub.tentative.html.ini
@@ -146,3 +146,6 @@
 
   [list-style-image sec-fetch-site - HTTPS downgrade-upgrade]
     expected: FAIL
+
+  [border-image sec-fetch-dest - Not sent to non-trustworthy cross-site destination]
+    expected: FAIL
diff --git a/tests/wpt/metadata-layout-2020/fetch/nosniff/parsing-nosniff.window.js.ini b/tests/wpt/metadata-layout-2020/fetch/nosniff/parsing-nosniff.window.js.ini
index 638a958a465..ba47e36f3af 100644
--- a/tests/wpt/metadata-layout-2020/fetch/nosniff/parsing-nosniff.window.js.ini
+++ b/tests/wpt/metadata-layout-2020/fetch/nosniff/parsing-nosniff.window.js.ini
@@ -8,11 +8,5 @@
   [X-Content-Type-Options%3A%20nosniff%0C]
     expected: FAIL
 
-  [X-Content-Type-Options%3A%20%40%23%24%23%25%25%26%5E%26%5E*()()11!%2Cnosniff]
-    expected: FAIL
-
-  [X-Content-Type-Options%3A%20no%0D%0AX-Content-Type-Options%3A%20nosniff]
-    expected: FAIL
-
   [X-Content-Type-Options%3A%20%2Cnosniff]
     expected: FAIL
diff --git a/tests/wpt/metadata-layout-2020/html/browsers/browsing-the-web/navigating-across-documents/005.html.ini b/tests/wpt/metadata-layout-2020/html/browsers/browsing-the-web/navigating-across-documents/005.html.ini
index f7ee5361549..33efcdbcf48 100644
--- a/tests/wpt/metadata-layout-2020/html/browsers/browsing-the-web/navigating-across-documents/005.html.ini
+++ b/tests/wpt/metadata-layout-2020/html/browsers/browsing-the-web/navigating-across-documents/005.html.ini
@@ -1,4 +1,3 @@
 [005.html]
-  expected: TIMEOUT
   [Link with onclick navigation and href navigation ]
     expected: FAIL
diff --git a/tests/wpt/metadata-layout-2020/html/browsers/browsing-the-web/navigating-across-documents/initial-empty-document/load-pageshow-events-iframe-contentWindow.html.ini b/tests/wpt/metadata-layout-2020/html/browsers/browsing-the-web/navigating-across-documents/initial-empty-document/load-pageshow-events-iframe-contentWindow.html.ini
index 149bcb4ff8c..51fd557bd7f 100644
--- a/tests/wpt/metadata-layout-2020/html/browsers/browsing-the-web/navigating-across-documents/initial-empty-document/load-pageshow-events-iframe-contentWindow.html.ini
+++ b/tests/wpt/metadata-layout-2020/html/browsers/browsing-the-web/navigating-across-documents/initial-empty-document/load-pageshow-events-iframe-contentWindow.html.ini
@@ -7,6 +7,3 @@
 
   [load & pageshow events do not fire on contentWindow of <iframe> element created with src='about:blank#foo']
     expected: FAIL
-
-  [load & pageshow events do not fire on contentWindow of <iframe> element created with src='about:blank']
-    expected: FAIL
diff --git a/tests/wpt/metadata-layout-2020/html/browsers/browsing-the-web/navigating-across-documents/javascript-url-no-beforeunload.window.js.ini b/tests/wpt/metadata-layout-2020/html/browsers/browsing-the-web/navigating-across-documents/javascript-url-no-beforeunload.window.js.ini
index 4b25ec32301..a06984505e9 100644
--- a/tests/wpt/metadata-layout-2020/html/browsers/browsing-the-web/navigating-across-documents/javascript-url-no-beforeunload.window.js.ini
+++ b/tests/wpt/metadata-layout-2020/html/browsers/browsing-the-web/navigating-across-documents/javascript-url-no-beforeunload.window.js.ini
@@ -5,3 +5,6 @@
 
   [Navigating an opened window via location.href to a javascript: URL must not fire beforeunload: string completion]
     expected: TIMEOUT
+
+  [Navigating an opened window with an iframe via location.href to a javascript: URL must not fire beforeunload on the iframe: undefined completion]
+    expected: FAIL
diff --git a/tests/wpt/metadata-layout-2020/html/browsers/browsing-the-web/navigating-across-documents/javascript-url-return-value-handling-dynamic.html.ini b/tests/wpt/metadata-layout-2020/html/browsers/browsing-the-web/navigating-across-documents/javascript-url-return-value-handling-dynamic.html.ini
index 8ae58f9f1e2..78240a2f463 100644
--- a/tests/wpt/metadata-layout-2020/html/browsers/browsing-the-web/navigating-across-documents/javascript-url-return-value-handling-dynamic.html.ini
+++ b/tests/wpt/metadata-layout-2020/html/browsers/browsing-the-web/navigating-across-documents/javascript-url-return-value-handling-dynamic.html.ini
@@ -16,6 +16,3 @@
 
   [D83D DE0D set in href="" targeting a frame and clicked]
     expected: FAIL
-
-  [DE0D 0041 set in href="" targeting a frame and clicked]
-    expected: FAIL
diff --git a/tests/wpt/metadata-layout-2020/html/browsers/browsing-the-web/navigating-across-documents/navigation-unload-cross-origin.sub.window.js.ini b/tests/wpt/metadata-layout-2020/html/browsers/browsing-the-web/navigating-across-documents/navigation-unload-cross-origin.sub.window.js.ini
deleted file mode 100644
index 4ecd6d9f753..00000000000
--- a/tests/wpt/metadata-layout-2020/html/browsers/browsing-the-web/navigating-across-documents/navigation-unload-cross-origin.sub.window.js.ini
+++ /dev/null
@@ -1,3 +0,0 @@
-[navigation-unload-cross-origin.sub.window.html]
-  [Cross-origin navigation started from unload handler must be ignored]
-    expected: FAIL
diff --git a/tests/wpt/metadata-layout-2020/html/browsers/browsing-the-web/navigating-across-documents/navigation-unload-same-origin.window.js.ini b/tests/wpt/metadata-layout-2020/html/browsers/browsing-the-web/navigating-across-documents/navigation-unload-same-origin.window.js.ini
new file mode 100644
index 00000000000..7dc346632a4
--- /dev/null
+++ b/tests/wpt/metadata-layout-2020/html/browsers/browsing-the-web/navigating-across-documents/navigation-unload-same-origin.window.js.ini
@@ -0,0 +1,3 @@
+[navigation-unload-same-origin.window.html]
+  [Same-origin navigation started from unload handler must be ignored]
+    expected: FAIL
diff --git a/tests/wpt/metadata-layout-2020/html/browsers/browsing-the-web/navigating-across-documents/replace-before-load/form-submit.html.ini b/tests/wpt/metadata-layout-2020/html/browsers/browsing-the-web/navigating-across-documents/replace-before-load/form-submit.html.ini
index f18f914e4a4..16371ab858d 100644
--- a/tests/wpt/metadata-layout-2020/html/browsers/browsing-the-web/navigating-across-documents/replace-before-load/form-submit.html.ini
+++ b/tests/wpt/metadata-layout-2020/html/browsers/browsing-the-web/navigating-across-documents/replace-before-load/form-submit.html.ini
@@ -1,3 +1,4 @@
 [form-submit.html]
+  expected: TIMEOUT
   [Replace before load, triggered by formElement.submit()]
-    expected: FAIL
+    expected: TIMEOUT
diff --git a/tests/wpt/metadata-layout-2020/html/browsers/history/the-history-interface/traverse-during-unload.html.ini b/tests/wpt/metadata-layout-2020/html/browsers/history/the-history-interface/traverse-during-unload.html.ini
new file mode 100644
index 00000000000..f5b7b25324f
--- /dev/null
+++ b/tests/wpt/metadata-layout-2020/html/browsers/history/the-history-interface/traverse-during-unload.html.ini
@@ -0,0 +1,4 @@
+[traverse-during-unload.html]
+  expected: TIMEOUT
+  [Traversing the history during unload]
+    expected: TIMEOUT
diff --git a/tests/wpt/metadata-layout-2020/html/semantics/embedded-content/the-iframe-element/sandbox-top-navigation-child-special-cases.tentative.sub.window.js.ini b/tests/wpt/metadata-layout-2020/html/semantics/embedded-content/the-iframe-element/sandbox-top-navigation-child-special-cases.tentative.sub.window.js.ini
index 31745fdcdcf..31928ad3947 100644
--- a/tests/wpt/metadata-layout-2020/html/semantics/embedded-content/the-iframe-element/sandbox-top-navigation-child-special-cases.tentative.sub.window.js.ini
+++ b/tests/wpt/metadata-layout-2020/html/semantics/embedded-content/the-iframe-element/sandbox-top-navigation-child-special-cases.tentative.sub.window.js.ini
@@ -1,4 +1,5 @@
 [sandbox-top-navigation-child-special-cases.tentative.sub.window.html]
+  expected: TIMEOUT
   [Allow top with user activation + user activation]
     expected: FAIL
 
diff --git a/tests/wpt/metadata-layout-2020/html/semantics/forms/historical.html.ini b/tests/wpt/metadata-layout-2020/html/semantics/forms/historical.html.ini
new file mode 100644
index 00000000000..5d8289307cc
--- /dev/null
+++ b/tests/wpt/metadata-layout-2020/html/semantics/forms/historical.html.ini
@@ -0,0 +1,3 @@
+[historical.html]
+  [<input name=isindex> should not be supported]
+    expected: FAIL
diff --git a/tests/wpt/metadata-layout-2020/html/semantics/links/links-created-by-a-and-area-elements/htmlanchorelement_noopener.html.ini b/tests/wpt/metadata-layout-2020/html/semantics/links/links-created-by-a-and-area-elements/htmlanchorelement_noopener.html.ini
index dcd52d2fee8..e0d30013daf 100644
--- a/tests/wpt/metadata-layout-2020/html/semantics/links/links-created-by-a-and-area-elements/htmlanchorelement_noopener.html.ini
+++ b/tests/wpt/metadata-layout-2020/html/semantics/links/links-created-by-a-and-area-elements/htmlanchorelement_noopener.html.ini
@@ -1,4 +1,5 @@
 [htmlanchorelement_noopener.html]
+  expected: TIMEOUT
   [Check that targeting of rel=noopener with a given name reuses an existing window with that name]
     expected: FAIL
 
@@ -9,4 +10,4 @@
     expected: FAIL
 
   [Check that rel=noopener with target=_self does a normal load]
-    expected: FAIL
+    expected: NOTRUN
diff --git a/tests/wpt/metadata-layout-2020/html/semantics/scripting-1/the-script-element/defer-script/async-script.html.ini b/tests/wpt/metadata-layout-2020/html/semantics/scripting-1/the-script-element/defer-script/async-script.html.ini
new file mode 100644
index 00000000000..1181798bd79
--- /dev/null
+++ b/tests/wpt/metadata-layout-2020/html/semantics/scripting-1/the-script-element/defer-script/async-script.html.ini
@@ -0,0 +1,4 @@
+[async-script.html]
+
+[async-script.html?reload]
+  expected: ERROR
diff --git a/tests/wpt/metadata-layout-2020/html/syntax/parsing/DOMContentLoaded-defer.html.ini b/tests/wpt/metadata-layout-2020/html/syntax/parsing/DOMContentLoaded-defer.html.ini
new file mode 100644
index 00000000000..b8bdf33cb65
--- /dev/null
+++ b/tests/wpt/metadata-layout-2020/html/syntax/parsing/DOMContentLoaded-defer.html.ini
@@ -0,0 +1,3 @@
+[DOMContentLoaded-defer.html]
+  [The end: DOMContentLoaded and defer scripts]
+    expected: FAIL
diff --git a/tests/wpt/metadata-layout-2020/html/webappapis/scripting/processing-model-2/integration-with-the-javascript-job-queue/promise-job-entry-different-function-realm.html.ini b/tests/wpt/metadata-layout-2020/html/webappapis/scripting/processing-model-2/integration-with-the-javascript-job-queue/promise-job-entry-different-function-realm.html.ini
index 7237f5792de..dbe1def99e3 100644
--- a/tests/wpt/metadata-layout-2020/html/webappapis/scripting/processing-model-2/integration-with-the-javascript-job-queue/promise-job-entry-different-function-realm.html.ini
+++ b/tests/wpt/metadata-layout-2020/html/webappapis/scripting/processing-model-2/integration-with-the-javascript-job-queue/promise-job-entry-different-function-realm.html.ini
@@ -1,10 +1,9 @@
 [promise-job-entry-different-function-realm.html]
-  expected: TIMEOUT
   [Fulfillment handler on fulfilled promise]
     expected: FAIL
 
   [Rejection handler on pending-then-rejected promise]
-    expected: TIMEOUT
+    expected: FAIL
 
   [Thenable resolution]
     expected: FAIL
@@ -13,4 +12,4 @@
     expected: FAIL
 
   [Fulfillment handler on pending-then-fulfilled promise]
-    expected: TIMEOUT
+    expected: FAIL
diff --git a/tests/wpt/metadata-layout-2020/performance-timeline/tentative/include-frames-from-child-cross-origin-grandchild.sub.html.ini b/tests/wpt/metadata-layout-2020/performance-timeline/tentative/include-frames-from-child-cross-origin-grandchild.sub.html.ini
new file mode 100644
index 00000000000..7110841423a
--- /dev/null
+++ b/tests/wpt/metadata-layout-2020/performance-timeline/tentative/include-frames-from-child-cross-origin-grandchild.sub.html.ini
@@ -0,0 +1,4 @@
+[include-frames-from-child-cross-origin-grandchild.sub.html]
+  expected: ERROR
+  [GetEntries of a Cross-Origin child frame with one Cross-Origin grandchild frame]
+    expected: TIMEOUT
diff --git a/tests/wpt/metadata-layout-2020/performance-timeline/tentative/include-frames-from-child-same-origin-grandchild.sub.html.ini b/tests/wpt/metadata-layout-2020/performance-timeline/tentative/include-frames-from-child-same-origin-grandchild.sub.html.ini
new file mode 100644
index 00000000000..5498d923404
--- /dev/null
+++ b/tests/wpt/metadata-layout-2020/performance-timeline/tentative/include-frames-from-child-same-origin-grandchild.sub.html.ini
@@ -0,0 +1,4 @@
+[include-frames-from-child-same-origin-grandchild.sub.html]
+  expected: ERROR
+  [GetEntries of a Cross-Origin child frame with one Same-Origin grandchild frame]
+    expected: TIMEOUT
diff --git a/tests/wpt/metadata-layout-2020/performance-timeline/tentative/include-frames-one-cross-origin-child-one-same-origin-grandchild.sub.html.ini b/tests/wpt/metadata-layout-2020/performance-timeline/tentative/include-frames-one-cross-origin-child-one-same-origin-grandchild.sub.html.ini
new file mode 100644
index 00000000000..1b028f5c0ed
--- /dev/null
+++ b/tests/wpt/metadata-layout-2020/performance-timeline/tentative/include-frames-one-cross-origin-child-one-same-origin-grandchild.sub.html.ini
@@ -0,0 +1,4 @@
+[include-frames-one-cross-origin-child-one-same-origin-grandchild.sub.html]
+  expected: ERROR
+  [GetEntries of a parent Frame with one Cross-Origin child and one Same-Origin grandchild]
+    expected: TIMEOUT
diff --git a/tests/wpt/metadata-layout-2020/performance-timeline/tentative/include-frames-one-same-origin-child-one-cross-origin-child.sub.html.ini b/tests/wpt/metadata-layout-2020/performance-timeline/tentative/include-frames-one-same-origin-child-one-cross-origin-child.sub.html.ini
new file mode 100644
index 00000000000..93df402e622
--- /dev/null
+++ b/tests/wpt/metadata-layout-2020/performance-timeline/tentative/include-frames-one-same-origin-child-one-cross-origin-child.sub.html.ini
@@ -0,0 +1,4 @@
+[include-frames-one-same-origin-child-one-cross-origin-child.sub.html]
+  expected: ERROR
+  [GetEntries of a parent Frame with one Cross-Origin child and one Same-Origin child]
+    expected: TIMEOUT
diff --git a/tests/wpt/metadata-layout-2020/performance-timeline/tentative/include-frames-one-same-origin-child-one-same-origin-grandchild.html.ini b/tests/wpt/metadata-layout-2020/performance-timeline/tentative/include-frames-one-same-origin-child-one-same-origin-grandchild.html.ini
new file mode 100644
index 00000000000..3c36bd59d1e
--- /dev/null
+++ b/tests/wpt/metadata-layout-2020/performance-timeline/tentative/include-frames-one-same-origin-child-one-same-origin-grandchild.html.ini
@@ -0,0 +1,4 @@
+[include-frames-one-same-origin-child-one-same-origin-grandchild.html]
+  expected: ERROR
+  [GetEntries of a parent Frame with one Same-Origin child and one Same-Origin grandchild]
+    expected: TIMEOUT
diff --git a/tests/wpt/metadata-layout-2020/performance-timeline/tentative/include-frames-one-same-origin-child.html.ini b/tests/wpt/metadata-layout-2020/performance-timeline/tentative/include-frames-one-same-origin-child.html.ini
new file mode 100644
index 00000000000..119a48720c4
--- /dev/null
+++ b/tests/wpt/metadata-layout-2020/performance-timeline/tentative/include-frames-one-same-origin-child.html.ini
@@ -0,0 +1,4 @@
+[include-frames-one-same-origin-child.html]
+  expected: ERROR
+  [GetEntries of a parent Frame with one Same-Origin child]
+    expected: TIMEOUT
diff --git a/tests/wpt/metadata-layout-2020/performance-timeline/tentative/include-frames-two-local-children.html.ini b/tests/wpt/metadata-layout-2020/performance-timeline/tentative/include-frames-two-local-children.html.ini
index 07fe4a75842..6eac8af1588 100644
--- a/tests/wpt/metadata-layout-2020/performance-timeline/tentative/include-frames-two-local-children.html.ini
+++ b/tests/wpt/metadata-layout-2020/performance-timeline/tentative/include-frames-two-local-children.html.ini
@@ -2,3 +2,6 @@
   expected: ERROR
   [GetEntries of a Parent Frame with two LocalFrame children]
     expected: TIMEOUT
+
+  [GetEntries of a parent Frame with two Same-Origin children]
+    expected: TIMEOUT
diff --git a/tests/wpt/metadata-layout-2020/performance-timeline/tentative/performance-entry-source.html.ini b/tests/wpt/metadata-layout-2020/performance-timeline/tentative/performance-entry-source.html.ini
new file mode 100644
index 00000000000..6d6c3f0fe97
--- /dev/null
+++ b/tests/wpt/metadata-layout-2020/performance-timeline/tentative/performance-entry-source.html.ini
@@ -0,0 +1,3 @@
+[performance-entry-source.html]
+  [PerformanceEntry source is equal to its respective Window]
+    expected: FAIL
diff --git a/tests/wpt/metadata-layout-2020/resource-timing/content-type-parsing.html.ini b/tests/wpt/metadata-layout-2020/resource-timing/content-type-parsing.html.ini
index 9f35c09a4a7..dea574899ad 100644
--- a/tests/wpt/metadata-layout-2020/resource-timing/content-type-parsing.html.ini
+++ b/tests/wpt/metadata-layout-2020/resource-timing/content-type-parsing.html.ini
@@ -25,40 +25,40 @@
     expected: FAIL
 
   [content-type 8 : text/plain;charset=gbk;x=foo,text/plain]
-    expected: TIMEOUT
+    expected: FAIL
 
   [content-type 9 : text/html;charset=gbk,text/plain,text/html]
-    expected: NOTRUN
+    expected: FAIL
 
   [content-type 10 : text/plain,*/*]
-    expected: NOTRUN
+    expected: FAIL
 
   [content-type 11 : text/html,*/*]
-    expected: NOTRUN
+    expected: FAIL
 
   [content-type 12 : */*,text/html]
-    expected: NOTRUN
+    expected: FAIL
 
   [content-type 13 : text/plain,*/*;charset=gbk]
-    expected: NOTRUN
+    expected: FAIL
 
   [content-type 14 : text/html,*/*;charset=gbk]
-    expected: NOTRUN
+    expected: FAIL
 
   [content-type 15 : text/html;x=",text/plain]
-    expected: NOTRUN
+    expected: FAIL
 
   [content-type 16 : text/html;",text/plain]
-    expected: NOTRUN
+    expected: FAIL
 
   [content-type 17 : text/html;",\\",text/plain]
-    expected: NOTRUN
+    expected: FAIL
 
   [content-type 18 : text/html;",\\",text/plain,";charset=GBK]
-    expected: NOTRUN
+    expected: FAIL
 
   [content-type 19 : text/html;",",text/plain]
-    expected: NOTRUN
+    expected: FAIL
 
   [mime-type 1 : text/html;charset=gbk]
     expected: NOTRUN
diff --git a/tests/wpt/metadata-layout-2020/webmessaging/broadcastchannel/cross-partition.https.tentative.html.ini b/tests/wpt/metadata-layout-2020/webmessaging/broadcastchannel/cross-partition.https.tentative.html.ini
index 39d039a0132..04c2032c723 100644
--- a/tests/wpt/metadata-layout-2020/webmessaging/broadcastchannel/cross-partition.https.tentative.html.ini
+++ b/tests/wpt/metadata-layout-2020/webmessaging/broadcastchannel/cross-partition.https.tentative.html.ini
@@ -1,5 +1,5 @@
 [cross-partition.https.tentative.html]
-  expected: CRASH
+  expected: TIMEOUT
   [BroadcastChannel messages aren't received from a cross-partition iframe]
     expected: FAIL
 
diff --git a/tests/wpt/metadata-layout-2020/webmessaging/with-ports/018.html.ini b/tests/wpt/metadata-layout-2020/webmessaging/with-ports/018.html.ini
deleted file mode 100644
index b7b36c1d3a4..00000000000
--- a/tests/wpt/metadata-layout-2020/webmessaging/with-ports/018.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[018.html]
-  expected: TIMEOUT
-  [origin of the script that invoked the method, javascript:]
-    expected: TIMEOUT
diff --git a/tests/wpt/metadata-layout-2020/webmessaging/without-ports/017.html.ini b/tests/wpt/metadata-layout-2020/webmessaging/without-ports/017.html.ini
deleted file mode 100644
index c7946fc91b4..00000000000
--- a/tests/wpt/metadata-layout-2020/webmessaging/without-ports/017.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[017.html]
-  expected: TIMEOUT
-  [origin of the script that invoked the method, about:blank]
-    expected: TIMEOUT
diff --git a/tests/wpt/metadata/FileAPI/url/url-in-tags-revoke.window.js.ini b/tests/wpt/metadata/FileAPI/url/url-in-tags-revoke.window.js.ini
index cdeaf7f7080..282ab0b2525 100644
--- a/tests/wpt/metadata/FileAPI/url/url-in-tags-revoke.window.js.ini
+++ b/tests/wpt/metadata/FileAPI/url/url-in-tags-revoke.window.js.ini
@@ -7,7 +7,7 @@
     expected: FAIL
 
   [Opening a blob URL in a new window immediately before revoking it works.]
-    expected: TIMEOUT
+    expected: FAIL
 
   [Opening a blob URL in a noopener about:blank window immediately before revoking it works.]
     expected: TIMEOUT
diff --git a/tests/wpt/metadata/MANIFEST.json b/tests/wpt/metadata/MANIFEST.json
index ff2be2dcc3c..af043a038f8 100644
--- a/tests/wpt/metadata/MANIFEST.json
+++ b/tests/wpt/metadata/MANIFEST.json
@@ -726,6 +726,13 @@
         {}
        ]
       ],
+      "grid-item-placement-crash.html": [
+       "e6cc6c8b519fa0e15faa4cda20903e76854875e0",
+       [
+        null,
+        {}
+       ]
+      ],
       "grid-large-end-border-crash.html": [
        "d2705f04f44d8e911837426d82bcd0296d9ac35c",
        [
@@ -28306,6 +28313,19 @@
        ],
        {}
       ]
+     ],
+     "inline-flexbox-vertical-rl-image-flexitem-crash-print.html": [
+      "0de07b187050bfa481152001936b49d5e114dccd",
+      [
+       null,
+       [
+        [
+         "/common/blank.html",
+         "!="
+        ]
+       ],
+       {}
+      ]
      ]
     },
     "css-fonts": {
@@ -141953,6 +141973,58 @@
        {}
       ]
      ],
+     "out-of-flow-in-multicolumn-100.html": [
+      "1bf71e832de9a2be139af258f6a4c25215d0a0b1",
+      [
+       null,
+       [
+        [
+         "/css/reference/ref-filled-green-100px-square.xht",
+         "=="
+        ]
+       ],
+       {}
+      ]
+     ],
+     "out-of-flow-in-multicolumn-101.html": [
+      "ed7e1e234d8aa0a12a61b68e5de93d10ce7a4ce5",
+      [
+       null,
+       [
+        [
+         "/css/reference/ref-filled-green-100px-square.xht",
+         "=="
+        ]
+       ],
+       {}
+      ]
+     ],
+     "out-of-flow-in-multicolumn-102.html": [
+      "45cbc0b4533c7c87fed3be713474202fe29e1f47",
+      [
+       null,
+       [
+        [
+         "/css/reference/ref-filled-green-100px-square.xht",
+         "=="
+        ]
+       ],
+       {}
+      ]
+     ],
+     "out-of-flow-in-multicolumn-103.html": [
+      "b54cbcd85a88a6e845adec74daefd43349ee4f13",
+      [
+       null,
+       [
+        [
+         "/css/reference/ref-filled-green-100px-square.xht",
+         "=="
+        ]
+       ],
+       {}
+      ]
+     ],
      "overflow-clip-000.html": [
       "72b10f5cdd3092a042f1f90bff04e9428d61608e",
       [
@@ -175177,6 +175249,19 @@
        {}
       ]
      ],
+     "font-variant-alternates-19.html": [
+      "6e9caf2e47cf8875a7756c8c2ce0ac7be2b22e26",
+      [
+       null,
+       [
+        [
+         "/css/css-fonts/font-variant-alternates-19-ref.html",
+         "=="
+        ]
+       ],
+       {}
+      ]
+     ],
      "font-variant-caps-01.html": [
       "9e96486e33f8ae964e1de2118218ecc88f1bff29",
       [
@@ -186072,7 +186157,7 @@
      ],
      "gradient": {
       "css-color-4-colors-default-to-oklab-gradient.html": [
-       "5be18ac30ff461779c5e441ced2b7f23cbf38a04",
+       "63fdd6f4a442ca49a8a11392dbf98de387467df0",
        [
         null,
         [
@@ -187363,12 +187448,168 @@
      ],
      "image-set": {
       "image-set-content-rendering.html": [
-       "9110837abd74213d1443d562fbe8794fc4f805a9",
+       "f0622a895061b8378bb06347a534db5b7bbbb5b7",
        [
         null,
         [
          [
-          "/css/css-images/image-set/image-set-content-rendering-ref.html",
+          "/css/css-images/image-set/reference/image-set-content-rendering-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
+      "image-set-dpi-rendering-2.html": [
+       "d7bd02e767731f8eec3366a0cc5b0c9ad782b91d",
+       [
+        null,
+        [
+         [
+          "/css/css-images/image-set/reference/image-set-rendering-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
+      "image-set-dpi-rendering.html": [
+       "be18e85ffb07e0833b92a1eccca5c02a15f9f942",
+       [
+        null,
+        [
+         [
+          "/css/css-images/image-set/reference/image-set-rendering-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
+      "image-set-dppx-rendering.html": [
+       "1fc2f8c85d94268e6c563806bb813991a14c5ac5",
+       [
+        null,
+        [
+         [
+          "/css/css-images/image-set/reference/image-set-rendering-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
+      "image-set-empty-url-rendering.html": [
+       "0286d7372f027acb3f5fb0e8f2295f375c3714d7",
+       [
+        null,
+        [
+         [
+          "/css/css-images/image-set/reference/image-set-rendering-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
+      "image-set-first-match-rendering.html": [
+       "4d5b9d7d9ce8d7ab84feec41bd25efd9f2e96908",
+       [
+        null,
+        [
+         [
+          "/css/css-images/image-set/reference/image-set-rendering-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
+      "image-set-invalid-resolution-rendering-2.html": [
+       "88917e1e3f769bc38fe65c33582202a45a47cf9d",
+       [
+        null,
+        [
+         [
+          "/css/css-images/image-set/reference/image-set-rendering-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
+      "image-set-invalid-resolution-rendering.html": [
+       "0cdcf6018e6513c4f3e5ce0afa413b6f46d30cf3",
+       [
+        null,
+        [
+         [
+          "/css/css-images/image-set/reference/image-set-rendering-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
+      "image-set-linear-gradient-rendering.html": [
+       "62f41a743f2b31ded22c273c0612e0d08974200b",
+       [
+        null,
+        [
+         [
+          "/css/css-images/image-set/reference/image-set-linear-gradient-rendering-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
+      "image-set-no-res-rendering.html": [
+       "927d4c67f1da268a55ce5008c9f84123031ba521",
+       [
+        null,
+        [
+         [
+          "/css/css-images/image-set/reference/image-set-rendering-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
+      "image-set-no-url-rendering.html": [
+       "7af722d7c06cf7e5df7eac7c051fe8056b781373",
+       [
+        null,
+        [
+         [
+          "/css/css-images/image-set/reference/image-set-rendering-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
+      "image-set-radial-gradient-rendering.html": [
+       "7bf950a403736e2629236aed42677e8fa9aa490c",
+       [
+        null,
+        [
+         [
+          "/css/css-images/image-set/reference/image-set-radial-gradient-rendering-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
+      "image-set-rendering-2.html": [
+       "a6724553d629606cced4f7966af06ead5afe6369",
+       [
+        null,
+        [
+         [
+          "/css/css-images/image-set/reference/image-set-rendering-ref.html",
           "=="
          ]
         ],
@@ -187376,12 +187617,12 @@
        ]
       ],
       "image-set-rendering.html": [
-       "eb3ece9654eb05e91e349b8ffa6f83af3c1af42a",
+       "ce4a900403dd5cccd6c1c5676b526f878932016c",
        [
         null,
         [
          [
-          "/css/css-images/image-set/image-set-rendering-ref.html",
+          "/css/css-images/image-set/reference/image-set-rendering-ref.html",
           "=="
          ]
         ],
@@ -187426,6 +187667,110 @@
         ],
         {}
        ]
+      ],
+      "image-set-type-first-match-rendering.html": [
+       "1283d22d1ff75ad1412ffd9f9ae895acdc69ce71",
+       [
+        null,
+        [
+         [
+          "/css/css-images/image-set/reference/image-set-rendering-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
+      "image-set-type-rendering-2.html": [
+       "897118acd602737e5e01d61f998bee3b7e9f25ef",
+       [
+        null,
+        [
+         [
+          "/css/css-images/image-set/reference/image-set-rendering-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
+      "image-set-type-rendering-3.html": [
+       "51dbe2c922189e4a67780089dc4a834d1ad9bc88",
+       [
+        null,
+        [
+         [
+          "/css/css-images/image-set/reference/image-set-rendering-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
+      "image-set-type-rendering.html": [
+       "16055dbccf7d9408cc249dd80f23f6255d7f8c78",
+       [
+        null,
+        [
+         [
+          "/css/css-images/image-set/reference/image-set-rendering-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
+      "image-set-type-skip-unsupported-rendering.html": [
+       "e555633cdda39fab6cc71a74c4abcb4dde0bf8c7",
+       [
+        null,
+        [
+         [
+          "/css/css-images/image-set/reference/image-set-rendering-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
+      "image-set-type-unsupported-rendering-2.html": [
+       "3f9fcd27d826eeea2b7ae470fec46984dd50cf16",
+       [
+        null,
+        [
+         [
+          "/css/css-images/image-set/reference/image-set-rendering-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
+      "image-set-type-unsupported-rendering.html": [
+       "6e9e56a4eb070a9e036ad064eb45401340b941ee",
+       [
+        null,
+        [
+         [
+          "/css/css-images/image-set/reference/image-set-rendering-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
+      "image-set-unordered-res-rendering.html": [
+       "c1063b74df613ba7fd0d365e7335dc3fb212f806",
+       [
+        null,
+        [
+         [
+          "/css/css-images/image-set/reference/image-set-rendering-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
       ]
      },
      "infinite-radial-gradient-refcrash.html": [
@@ -187679,7 +188024,7 @@
       ]
      ],
      "object-fit-contain-png-001c.html": [
-      "4fb7f113897e22dbf6eec0b7c9c9a83b136ebd8d",
+      "0f8195157e310cd69c05dcfd8a786972b981d2f1",
       [
        null,
        [
@@ -187688,7 +188033,23 @@
          "=="
         ]
        ],
-       {}
+       {
+        "fuzzy": [
+         [
+          null,
+          [
+           [
+            0,
+            20
+           ],
+           [
+            0,
+            2000
+           ]
+          ]
+         ]
+        ]
+       }
       ]
      ],
      "object-fit-contain-png-001e.html": [
@@ -187744,7 +188105,7 @@
       ]
      ],
      "object-fit-contain-png-002c.html": [
-      "738c015a52e471528dd7855e7e75ff064bc6a881",
+      "14834316a32efbf8f80c4612a93951e0fa792c51",
       [
        null,
        [
@@ -187753,7 +188114,23 @@
          "=="
         ]
        ],
-       {}
+       {
+        "fuzzy": [
+         [
+          null,
+          [
+           [
+            0,
+            20
+           ],
+           [
+            0,
+            2000
+           ]
+          ]
+         ]
+        ]
+       }
       ]
      ],
      "object-fit-contain-png-002e.html": [
@@ -188589,7 +188966,7 @@
       ]
      ],
      "object-fit-fill-png-001c.html": [
-      "36031175e63f751e7d46af6cd43d92485e8af544",
+      "0e2a3883fe2f05a2c89dbc0d87617aa965097330",
       [
        null,
        [
@@ -188598,7 +188975,23 @@
          "=="
         ]
        ],
-       {}
+       {
+        "fuzzy": [
+         [
+          null,
+          [
+           [
+            0,
+            20
+           ],
+           [
+            0,
+            3200
+           ]
+          ]
+         ]
+        ]
+       }
       ]
      ],
      "object-fit-fill-png-001e.html": [
@@ -188654,7 +189047,7 @@
       ]
      ],
      "object-fit-fill-png-002c.html": [
-      "a332c37f4f043650e1052d18a67e86bd6fc1cdfa",
+      "43bcced9f26c672c641bd5e1c6e48855ad1b23dc",
       [
        null,
        [
@@ -188663,7 +189056,23 @@
          "=="
         ]
        ],
-       {}
+       {
+        "fuzzy": [
+         [
+          null,
+          [
+           [
+            0,
+            20
+           ],
+           [
+            0,
+            3200
+           ]
+          ]
+         ]
+        ]
+       }
       ]
      ],
      "object-fit-fill-png-002e.html": [
@@ -296591,6 +297000,19 @@
        ],
        {}
       ]
+     ],
+     "fullscreen-root-fills-page.html": [
+      "f122e678f3fcd1b4c3c2d4673473a73a40a2ea3f",
+      [
+       null,
+       [
+        [
+         "/fullscreen/rendering/fullscreen-root-fills-page-ref.html",
+         "=="
+        ]
+       ],
+       {}
+      ]
      ]
     }
    },
@@ -367065,6 +367487,10 @@
       "cd54bef9a8cfde39273d375c9373ae4ee26fd6f3",
       []
      ],
+     "font-variant-alternates-19-ref.html": [
+      "22c178c64f22d558d9cd725f75ae06e0f01ccfd8",
+      []
+     ],
      "font-variant-caps-01-ref.html": [
       "68f9ef0c002b36172d07f7357dceeb95851c241e",
       []
@@ -375758,18 +376184,34 @@
       []
      ],
      "image-set": {
-      "image-set-content-rendering-ref.html": [
-       "29316bc1a6b17ecb479bb461a62c6f1011da877a",
-       []
-      ],
-      "image-set-rendering-ref.html": [
-       "081766ce7dbd271ac53fc4af96b19cea4fb095eb",
-       []
-      ],
       "image-set-resolution-001-ref.html": [
        "46c4d729ed59525b1a138f1f60aa6e6074251211",
        []
-      ]
+      ],
+      "reference": {
+       "image-set-content-rendering-ref.html": [
+        "c1ef6d4531cc13aef85c785d92ac42f5e8e4de77",
+        []
+       ],
+       "image-set-linear-gradient-rendering-ref.html": [
+        "272bab9c58281997f574ce0f6388544fcc9c0ba9",
+        []
+       ],
+       "image-set-radial-gradient-rendering-ref.html": [
+        "f5545af5e6b142e45d0a5b8a2cda4f38896198ae",
+        []
+       ],
+       "image-set-rendering-ref.html": [
+        "2ca6b3352d1060ffa6ea4747de6fee64983827f9",
+        []
+       ]
+      },
+      "resources": {
+       "image-set-rendering-helper.js": [
+        "7dbd50af88256bf507c0039110d7e863b2808e40",
+        []
+       ]
+      }
      },
      "infinite-radial-gradient-crash-ref.html": [
       "a80236dcf75c22ecd8e43935d004f1fddf0550cb",
@@ -380213,7 +380655,7 @@
      ],
      "resources": {
       "utils.js": [
-       "fca6093471d53d064eabeeee46467869b878886b",
+       "c9a0c73828f12cde80df54880802914501af1895",
        []
       ]
      },
@@ -389127,7 +389569,7 @@
       "properties": {
        "resources": {
         "testsuite.js": [
-         "a365f001316e66c0a3102b784a3f8ffe522fe404",
+         "2c0df9110d09b44b509c745c8d86033e3e543125",
          []
         ]
        }
@@ -402212,6 +402654,10 @@
      "backdrop-object-ref.html": [
       "6c7071a727dd27d182ae017e9f6dbc0834361ddc",
       []
+     ],
+     "fullscreen-root-fills-page-ref.html": [
+      "b2bf13557a2c3540645e3aa45a0850a61f8f0b28",
+      []
      ]
     },
     "trusted-click.js": [
@@ -402256,7 +402702,7 @@
       []
      ],
      "iframe_sensor_handler.html": [
-      "23e8e1bb94d4d7be4719e3b6a93cb09fcceefa61",
+      "4528c57a6beeec84bc00e311be0691e595b2f167",
       []
      ]
     }
@@ -422579,8 +423025,12 @@
       "02aafbb5c78368c69dbf1cdae81b432d988e17d1",
       []
      ],
-     "parent-frame-with-child.sub.html": [
-      "32dd4cb48bc2cba536b991dcfdff9e9adbd649c9",
+     "parent-frame-with-cross-origin-child.sub.html": [
+      "4be0df872cbfd22dfcbd6b4e8e9005a7a79e88ae",
+      []
+     ],
+     "parent-frame-with-same-origin-child.html": [
+      "c9248a4e8bb9f4107be82947436e469c3c74aaa6",
       []
      ],
      "postmessage-entry.html": [
@@ -423529,6 +423979,18 @@
       "1d3d21f4d953ee1eac4fbc93e91f4a404d5f0c8f",
       []
      ],
+     "prefetch-exec.html": [
+      "1d6765bc93e4496fbd0c87dbca9c5b7a3ab5b48e",
+      []
+     ],
+     "prefetch-helper.js": [
+      "cf0e0d583cd937664cee79d7c9fe0566f56f0288",
+      []
+     ],
+     "prefetch-info.py": [
+      "04d942ba05e6ba837f7b2f9eba0779a24e63d88a",
+      []
+     ],
      "preload_helper.js": [
       "5b7a6eb52ba0ef89834d040d4dfb95f299416489",
       []
@@ -429881,6 +430343,12 @@
    },
    "speculation-rules": {
     "prefetch": {
+     "no-vary-search": {
+      "README.txt": [
+       "60ac226f8cd4c8f82f0df9cf641cbe26ac39fed5",
+       []
+      ]
+     },
      "resources": {
       "authenticate.py": [
        "037a7c144e0ba6d14aec7e7108d161c049f46dd8",
@@ -429994,6 +430462,10 @@
        "7be73c8c6f2e856b49b9127e959e3e23796e749a",
        []
       ],
+      "csp-script-src-elem-inline-speculation-rules.html": [
+       "19aff92206f06ec19b6351398b2b351064eedbf5",
+       []
+      ],
       "csp-script-src-inline-speculation-rules.html": [
        "febfbd01ba125c1deef934b1ff4d78e3f2b0e164",
        []
@@ -430127,7 +430599,7 @@
        []
       ],
       "notification-on-activation.html": [
-       "03e36f06c134e1ee0ced6c703d1b8e20f1c7511b",
+       "0a85746b04142d55a351b9e2df1c5db4c815a82d",
        []
       ],
       "post-message-prerendering-completion-notification.html": [
@@ -441296,7 +441768,7 @@
    "trust-tokens": {
     "end-to-end": {
      "README.txt": [
-      "a86468df9d6b21dfc361d178eb3afc4b3c865fea",
+      "82d3cc844bdc726a37479fe6ce995ed1fd8649d6",
       []
      ]
     }
@@ -443743,7 +444215,7 @@
      []
     ],
     "video-encoder-utils.js": [
-     "fad6b909505feddbf32d9bb26392de5649e8e9c5",
+     "7201e054d81b54a17f2343727a2708c7d5f89722",
      []
     ],
     "videoFrame-construction.crossOriginIsolated.https.any.js.headers": [
@@ -443821,6 +444293,12 @@
         "006b91fc3a6812dad0116494d71b1f0da34651f9",
         []
        ],
+       "classic_interop": {
+        "__init__.py": [
+         "e69de29bb2d1d6434b8b29ae775ad8c2e48c5391",
+         []
+        ]
+       },
        "close": {
         "__init__.py": [
          "e69de29bb2d1d6434b8b29ae775ad8c2e48c5391",
@@ -444743,7 +445221,7 @@
      []
     ],
     "RTCRtpParameters-helper.js": [
-     "d7653c3a8afbfe60c7eeb64fe50ba250c271ce48",
+     "dd8ae0cc06d28b29865e61c5365600cbed465f35",
      []
     ],
     "RTCStats-helper.js": [
@@ -444788,7 +445266,7 @@
     },
     "simulcast": {
      "simulcast.js": [
-      "bede0a1d4e6901b7b9446131c7ef8e773a85d6fb",
+      "34605d4031d76f81f2bc189073faf13c9139821c",
       []
      ]
     },
@@ -476206,7 +476684,7 @@
       ]
      ],
      "invalid-characters-in-policy.html": [
-      "bd884c6fbd155a24e0348550de5f3faf6af60291",
+      "e46449117f65621dbe26abfb6192c63190270316",
       [
        null,
        {}
@@ -483494,6 +483972,20 @@
        {}
       ]
      ],
+     "missing-values-first-keyframe.html": [
+      "311e26259c7f0cb5a799018218b249acaf84acf5",
+      [
+       null,
+       {}
+      ]
+     ],
+     "missing-values-last-keyframe.html": [
+      "04c4eba45e4d5d112839244467eddacc5bac4412",
+      [
+       null,
+       {}
+      ]
+     ],
      "parsing": {
       "animation-composition-computed.tentative.html": [
        "535a40c9ca9d5c875b2b9eb7f7a16b22d55071fe",
@@ -484708,7 +485200,7 @@
       ]
      ],
      "inheritance.html": [
-      "d18106faf6926c229c6470a90a6f17355bc99474",
+      "bf10aeeb8e095645218d2504916775b4ee00ada9",
       [
        null,
        {}
@@ -486916,6 +487408,13 @@
         {}
        ]
       ],
+      "content-visibility-auto-state-changed-first-observation.html": [
+       "1c51851488199db10c8bfef392f48114fd35147e",
+       [
+        null,
+        {}
+       ]
+      ],
       "content-visibility-auto-state-changed.html": [
        "a65db6a2f82675586cc1f87d09ee5694e16334a4",
        [
@@ -490318,7 +490817,7 @@
        ]
       ],
       "font-variant-alternates-invalid.html": [
-       "baf35acb8a11d8d5319712b68191529f175d895b",
+       "8cd17d0849f4241a012de4523429483305d9e7ea",
        [
         null,
         {}
@@ -496768,6 +497267,13 @@
        {}
       ]
      ],
+     "scrollable-overflow-zero-one-axis.html": [
+      "1986a8d48b98fde17fda826c5bbf9d75d870f45e",
+      [
+       null,
+       {}
+      ]
+     ],
      "scrollbar-gutter-001.html": [
       "4486471cde560c24058fb168f43629f8da833654",
       [
@@ -497617,6 +498123,106 @@
        {}
       ]
      ],
+     "animation": {
+      "custom-property-animation-angle.html": [
+       "0cb06aef0bd825629c9d253824f2e783dc8b84c9",
+       [
+        null,
+        {}
+       ]
+      ],
+      "custom-property-animation-color.html": [
+       "001fc407e7ba96a277de1a6558883d8fd0ac23a0",
+       [
+        null,
+        {}
+       ]
+      ],
+      "custom-property-animation-custom-ident.html": [
+       "3f210f914b35806461c87ff7080d067c41702211",
+       [
+        null,
+        {}
+       ]
+      ],
+      "custom-property-animation-image.html": [
+       "935d3025d4a64c049bb8ad5d6246fd1dbfe3c36a",
+       [
+        null,
+        {}
+       ]
+      ],
+      "custom-property-animation-inherited-used-by-standard-property.html": [
+       "231ecca8c7977f0d9c0273d5a7bb85a4964e6260",
+       [
+        null,
+        {}
+       ]
+      ],
+      "custom-property-animation-integer.html": [
+       "400308a92eadaea6fc158ebd6e6528e333a061ad",
+       [
+        null,
+        {}
+       ]
+      ],
+      "custom-property-animation-length-percentage.html": [
+       "096efd6ba7f8f9d741a8f67589ed6e7c3029047b",
+       [
+        null,
+        {}
+       ]
+      ],
+      "custom-property-animation-length.html": [
+       "8849bf52d6651338444ea4b8024e4233d36f29f4",
+       [
+        null,
+        {}
+       ]
+      ],
+      "custom-property-animation-non-inherited-used-by-standard-property.html": [
+       "11d3f6740d950b8f86536515242869e468e1a1c3",
+       [
+        null,
+        {}
+       ]
+      ],
+      "custom-property-animation-number.html": [
+       "ea28acacf680fc2b45fcb93ab4d380fbd7bceadd",
+       [
+        null,
+        {}
+       ]
+      ],
+      "custom-property-animation-percentage.html": [
+       "6af498e702550fb6f98a9aebc591410d93213f05",
+       [
+        null,
+        {}
+       ]
+      ],
+      "custom-property-animation-resolution.html": [
+       "3d05139edcadfb926ce031347565082d318cd5c8",
+       [
+        null,
+        {}
+       ]
+      ],
+      "custom-property-animation-time.html": [
+       "b9f5984db7c53fb3294714c4c9d6cd5c8a43e019",
+       [
+        null,
+        {}
+       ]
+      ],
+      "custom-property-animation-url.html": [
+       "00ea48557feff9fd343bbe3a27810e8fea28bcf9",
+       [
+        null,
+        {}
+       ]
+      ]
+     },
      "at-property-animation.html": [
       "89ed671fdf1d838ee4a5c7f87e02b6bf1c6e4470",
       [
@@ -506141,7 +506747,7 @@
        ]
       ],
       "cssTransformValue.tentative.html": [
-       "e313647fa569121c1326217635979f275aab87b7",
+       "856b9314d852b7134dae6ad52ff391a61d6a0345",
        [
         null,
         {}
@@ -510827,7 +511433,7 @@
       ]
      ],
      "CSSFontFeatureValuesRule.html": [
-      "a267675cbaddab2324f818cd3138d8d52a5b20b1",
+      "a0ea64a5038a2197713fcb101a5ec077fed33845",
       [
        null,
        {}
@@ -594060,6 +594666,15 @@
          {}
         ]
        ],
+       "password-delete-space.html": [
+        "78b3c966b80af368030bc4520cd76087c5203cfd",
+        [
+         null,
+         {
+          "testdriver": true
+         }
+        ]
+       ],
        "password.html": [
         "aac54aa1c72252d2e32355456407ce4d10cb33e2",
         [
@@ -595819,7 +596434,7 @@
        ]
       ],
       "popover-light-dismiss.tentative.html": [
-       "bdd0d12545f03e54f1b111cb492899373eddad7a",
+       "83573c86f06f838a8d810e01c4d9f95eee256526",
        [
         null,
         {
@@ -623608,43 +624223,64 @@
        {}
       ]
      ],
-     "include-frames-one-local-child-one-local-grandchild.html": [
-      "ee2dadde8f997b4e1902362ca67de8e51a88025a",
+     "include-frames-from-child-cross-origin-grandchild.sub.html": [
+      "1886f040ec60d212f529ab1c18440792669b9375",
       [
        null,
        {}
       ]
      ],
-     "include-frames-one-local-child-one-remote-child.sub.html": [
-      "8e1ca9774fa15bdf4abbafe58276b71f6a29032d",
+     "include-frames-from-child-same-origin-grandchild.sub.html": [
+      "16142ca953a0b9da887354ee4dfa80276b0bef71",
       [
        null,
        {}
       ]
      ],
-     "include-frames-one-local-child.html": [
-      "46d4079fd20fb6d9c66cc9b4d6283ee53a13d09d",
-      [
-       null,
-       {}
-      ]
-     ],
-     "include-frames-one-remote-child-one-local-grandchild.sub.html": [
-      "a9efe4146161fbb0296a2612c8e2a489a620c000",
+     "include-frames-one-cross-origin-child-one-same-origin-grandchild.sub.html": [
+      "8aa5df778fef3dc18d450377e6a3ec0c3c31a2f8",
       [
        null,
        {}
       ]
      ],
      "include-frames-one-remote-child.sub.html": [
-      "822924c18b628e137a8d8518345da2bd0b372576",
+      "61e7a1f6480bdc122a87cce1b6d38a22c8db2ca7",
+      [
+       null,
+       {}
+      ]
+     ],
+     "include-frames-one-same-origin-child-one-cross-origin-child.sub.html": [
+      "b20bde93eed06c052098d42b8c747e23cc3ba3ff",
+      [
+       null,
+       {}
+      ]
+     ],
+     "include-frames-one-same-origin-child-one-same-origin-grandchild.html": [
+      "10ccea3da8842d36c98881e58ba528cc88864df0",
+      [
+       null,
+       {}
+      ]
+     ],
+     "include-frames-one-same-origin-child.html": [
+      "73dc417fe6e106e7b0e0d7636a55c74dffd441aa",
       [
        null,
        {}
       ]
      ],
      "include-frames-two-local-children.html": [
-      "d0274050dbd271e785a240957bd6965490a09d66",
+      "01d484452212a5181589dc0191c9cd24640bdeca",
+      [
+       null,
+       {}
+      ]
+     ],
+     "performance-entry-source.html": [
+      "5e51ddbbe4493dfdd0de1f9c8f53723d50aae53c",
       [
        null,
        {}
@@ -625347,7 +625983,7 @@
      ]
     ],
     "pointerevent_pointercapture_in_frame.html": [
-     "c4332ac459f571762a726210b0c791dfebbc1654",
+     "9edacd7d234633ebec2a12c0e42a4eb5b469c7aa",
      [
       "pointerevents/pointerevent_pointercapture_in_frame.html?mouse",
       {
@@ -626610,6 +627246,13 @@
       }
      ]
     ],
+    "prefetch-accept.html": [
+     "3820b9b4db058501bdabf9a7626e8142d8ef6673",
+     [
+      null,
+      {}
+     ]
+    ],
     "preload-connect-to-doc.html": [
      "ba45f6f3f848068ee9120b89c41307af22d570d3",
      [
@@ -642708,14 +643351,14 @@
       ]
      ],
      "animation-shorthand.html": [
-      "832b3e0cb9be89d4a5f04c5f05fe4cf76e860fa1",
+      "60d6c7664672b61a40f4b20e0fa89765d2bf67f4",
       [
        null,
        {}
       ]
      ],
      "animation-timeline-computed.html": [
-      "29486a02c1940288c03fb257dc72b9511d593300",
+      "a77233aab901de334e98f2e643e82a19cf8093c6",
       [
        null,
        {}
@@ -642757,7 +643400,7 @@
       ]
      ],
      "animation-timeline-parsing.html": [
-      "5691026dbccc3ca2982026d04d9ac1e225b378f4",
+      "dc22778fa7a94094b7be14d176312a01fd145f9b",
       [
        null,
        {}
@@ -651240,6 +651883,15 @@
        }
       ]
      ],
+     "csp-script-src-elem-inline-speculation-rules.tentative.html": [
+      "0a3b3b8a70ad1a5416b1014658c949f4d24c3bcf",
+      [
+       null,
+       {
+        "timeout": "long"
+       }
+      ]
+     ],
      "csp-script-src-inline-speculation-rules.tentative.html": [
       "923598bd2735623782905e8f9484e357cf16524c",
       [
@@ -660281,7 +660933,7 @@
    "trust-tokens": {
     "end-to-end": {
      "has-trust-token-with-no-top-frame.tentative.https.html": [
-      "38ebed9119aae3d2ed3c6d2d268231c96e2211b5",
+      "587c641d8dca9ef5ce17f169cdd2e4430d2ac144",
       [
        null,
        {}
@@ -668827,7 +669479,7 @@
       ]
      ],
      "columnGap.html": [
-      "fa85272d49df7932f2a91708b5c54b6a9b15f766",
+      "43d44152cb510e647c4ab6e11f48785c7e4c0eac",
       [
        null,
        {}
@@ -668862,14 +669514,14 @@
       ]
      ],
      "lineHeight.html": [
-      "16c12a7456a0e0c56015144b7c9331a6b004f195",
+      "03d45e54c168e5d9b2e6bf39a8d0b40793b73a3d",
       [
        null,
        {}
       ]
      ],
      "minHeight.html": [
-      "7055b53f147a67163180046c42d2b18231d4099d",
+      "07474bc3f44e067b7c5097a3c30f96fd39842e45",
       [
        null,
        {}
@@ -668904,7 +669556,7 @@
       ]
      ],
      "perspective.html": [
-      "2c2852639aa3fee6422be930195022ce50a8123d",
+      "f32b4dbad326e780355b1530ac41496cd8602b27",
       [
        null,
        {}
@@ -668918,7 +669570,7 @@
       ]
      ],
      "rowGap.html": [
-      "ad184610ce2a28ffe25dea962cf915c85e0f349b",
+      "b7dae62f238fb39d886c71bb8df616bcbdb30d8b",
       [
        null,
        {}
@@ -674510,7 +675162,7 @@
      ]
     ],
     "reconfiguring-encoder.https.any.js": [
-     "c380fa772ff6ac1df9aa5ecf1a7fe8f65df73c60",
+     "7bc7402b0119e4984260a880861f1e854a8756aa",
      [
       "webcodecs/reconfiguring-encoder.https.any.html?av1",
       {
@@ -675331,7 +675983,7 @@
      ]
     ],
     "video-encoder.https.any.js": [
-     "063be1ef0fd40bd3674715ebaa67f6ea2fed3f26",
+     "b5c511d4062cc5bf473dfbb670491d02c1daa19e",
      [
       "webcodecs/video-encoder.https.any.html",
       {
@@ -678297,7 +678949,7 @@
      ]
     ],
     "RTCPeerConnection-addTransceiver.https.html": [
-     "68a2623391b5fa511ed80d272245f860fbaeac8c",
+     "3fd83a76fe2f687114de006bc877bc915a1809be",
      [
       null,
       {}
@@ -678721,7 +679373,7 @@
      ]
     ],
     "RTCRtpParameters-encodings.html": [
-     "e1a6e625379ef1f6a87558a744fc1364c8896481",
+     "b68347cbaf92814b1a9c8cddc7c0bbc7a6c79676",
      [
       null,
       {}
@@ -678742,7 +679394,7 @@
      ]
     ],
     "RTCRtpParameters-transactionId.html": [
-     "a7b7865532b877e17bf17edab0ab44ec3ca288d4",
+     "2aa43f48573677f855efaae3b884143ff6277738",
      [
       null,
       {}
@@ -679290,6 +679942,16 @@
        }
       ]
      ],
+     "negotiation-encodings.https.html": [
+      "db690a9606c416fd129c91af92ccd7b090c7cc2a",
+      [
+       null,
+       {
+        "testdriver": true,
+        "timeout": "long"
+       }
+      ]
+     ],
      "rid-manipulation.html": [
       "a88506305a1d58944e6e6c2f01b26d8aef882909",
       [
@@ -679301,7 +679963,17 @@
       ]
      ],
      "setParameters-active.https.html": [
-      "86afa4082e27e5b6afa43f3e2a1f71766511dcc7",
+      "36f096add385d86bab2aaab16c58f98a2c48c2c4",
+      [
+       null,
+       {
+        "testdriver": true,
+        "timeout": "long"
+       }
+      ]
+     ],
+     "setParameters-encodings.https.html": [
+      "fb33529db6ff47354055f23de2699588e7630836",
       [
        null,
        {
@@ -679543,7 +680215,7 @@
      ]
     ],
     "RTCRtpParameters-maxFramerate.html": [
-     "c1d472386009d693835263483959a83d0e898048",
+     "3e348f0d147bdb6cd0583d4f5596feb30f86cb52",
      [
       null,
       {}
@@ -723513,6 +724185,15 @@
      },
      "bidi": {
       "browsing_context": {
+       "classic_interop": {
+        "window_handle.py": [
+         "4f36fba1973cd84e8fe2059741af677f6e6e0594",
+         [
+          null,
+          {}
+         ]
+        ]
+       },
        "close": {
         "close.py": [
          "21bf7411e563c11179abfee8fd740edece1ea277",
diff --git a/tests/wpt/metadata/css/CSS2/floats/hit-test-floats-002.html.ini b/tests/wpt/metadata/css/CSS2/floats/hit-test-floats-002.html.ini
new file mode 100644
index 00000000000..968f62a2553
--- /dev/null
+++ b/tests/wpt/metadata/css/CSS2/floats/hit-test-floats-002.html.ini
@@ -0,0 +1,3 @@
+[hit-test-floats-002.html]
+  [Hit test float]
+    expected: FAIL
diff --git a/tests/wpt/metadata/css/CSS2/normal-flow/block-in-inline-hittest-002.html.ini b/tests/wpt/metadata/css/CSS2/normal-flow/block-in-inline-hittest-002.html.ini
index 51432362d66..ee34bc91078 100644
--- a/tests/wpt/metadata/css/CSS2/normal-flow/block-in-inline-hittest-002.html.ini
+++ b/tests/wpt/metadata/css/CSS2/normal-flow/block-in-inline-hittest-002.html.ini
@@ -1,3 +1,6 @@
 [block-in-inline-hittest-002.html]
   [elementsFromPoint]
     expected: FAIL
+
+  [elementFromPoint]
+    expected: FAIL
diff --git a/tests/wpt/metadata/css/CSS2/normal-flow/block-in-inline-hittest-float-002.html.ini b/tests/wpt/metadata/css/CSS2/normal-flow/block-in-inline-hittest-float-002.html.ini
deleted file mode 100644
index 3e5096beef3..00000000000
--- a/tests/wpt/metadata/css/CSS2/normal-flow/block-in-inline-hittest-float-002.html.ini
+++ /dev/null
@@ -1,3 +0,0 @@
-[block-in-inline-hittest-float-002.html]
-  [block-in-inline-hittest-float-002]
-    expected: FAIL
diff --git a/tests/wpt/metadata/css/css-animations/missing-values-first-keyframe.html.ini b/tests/wpt/metadata/css/css-animations/missing-values-first-keyframe.html.ini
new file mode 100644
index 00000000000..303457f9ba4
--- /dev/null
+++ b/tests/wpt/metadata/css/css-animations/missing-values-first-keyframe.html.ini
@@ -0,0 +1,3 @@
+[missing-values-first-keyframe.html]
+  [Missing property values in the first keyframe are correctly interpolated from a neutral keyframe value]
+    expected: FAIL
diff --git a/tests/wpt/metadata/css/css-animations/missing-values-last-keyframe.html.ini b/tests/wpt/metadata/css/css-animations/missing-values-last-keyframe.html.ini
new file mode 100644
index 00000000000..855cf2cc9ce
--- /dev/null
+++ b/tests/wpt/metadata/css/css-animations/missing-values-last-keyframe.html.ini
@@ -0,0 +1,3 @@
+[missing-values-last-keyframe.html]
+  [Missing property values in the last keyframe are correctly interpolated from a neutral keyframe value]
+    expected: FAIL
diff --git a/tests/wpt/metadata/css/css-flexbox/abspos/position-absolute-013.html.ini b/tests/wpt/metadata/css/css-flexbox/abspos/position-absolute-013.html.ini
index 80111fb0236..2b2e0fce8eb 100644
--- a/tests/wpt/metadata/css/css-flexbox/abspos/position-absolute-013.html.ini
+++ b/tests/wpt/metadata/css/css-flexbox/abspos/position-absolute-013.html.ini
@@ -1,4 +1,5 @@
 [position-absolute-013.html]
+  expected: TIMEOUT
   [.flexbox 309]
     expected: FAIL
 
diff --git a/tests/wpt/metadata/css/css-fonts/variations/at-font-face-font-matching.html.ini b/tests/wpt/metadata/css/css-fonts/variations/at-font-face-font-matching.html.ini
index a345330f229..4f51397e0af 100644
--- a/tests/wpt/metadata/css/css-fonts/variations/at-font-face-font-matching.html.ini
+++ b/tests/wpt/metadata/css/css-fonts/variations/at-font-face-font-matching.html.ini
@@ -328,3 +328,9 @@
 
   [Matching font-style: 'italic' should prefer 'oblique 30deg 60deg' over 'oblique 40deg 50deg']
     expected: FAIL
+
+  [Matching font-weight: '501' should prefer '503 520' over '500']
+    expected: FAIL
+
+  [Matching font-style: 'oblique -10deg' should prefer 'oblique -50deg -40deg' over 'italic']
+    expected: FAIL
diff --git a/tests/wpt/metadata/css/css-transitions/properties-value-001.html.ini b/tests/wpt/metadata/css/css-transitions/properties-value-001.html.ini
index c4daffd168f..3094ea29f3c 100644
--- a/tests/wpt/metadata/css/css-transitions/properties-value-001.html.ini
+++ b/tests/wpt/metadata/css/css-transitions/properties-value-001.html.ini
@@ -52,3 +52,153 @@
 
   [background-position length(px) / events]
     expected: FAIL
+
+  [padding-bottom length(ex) / values]
+    expected: FAIL
+
+  [padding-bottom length(mm) / values]
+    expected: FAIL
+
+  [padding-bottom length(cm) / values]
+    expected: FAIL
+
+  [padding-bottom length(in) / values]
+    expected: FAIL
+
+  [padding-left length(pt) / values]
+    expected: FAIL
+
+  [padding-left length(pc) / values]
+    expected: FAIL
+
+  [padding-left length(px) / values]
+    expected: FAIL
+
+  [padding-left length(em) / values]
+    expected: FAIL
+
+  [padding-left length(ex) / values]
+    expected: FAIL
+
+  [padding-left length(mm) / values]
+    expected: FAIL
+
+  [padding-left length(cm) / values]
+    expected: FAIL
+
+  [padding-left length(in) / values]
+    expected: FAIL
+
+  [padding-right length(pt) / values]
+    expected: FAIL
+
+  [padding-right length(pc) / values]
+    expected: FAIL
+
+  [padding-right length(px) / values]
+    expected: FAIL
+
+  [padding-right length(em) / values]
+    expected: FAIL
+
+  [padding-right length(ex) / values]
+    expected: FAIL
+
+  [padding-right length(mm) / values]
+    expected: FAIL
+
+  [padding-right length(cm) / values]
+    expected: FAIL
+
+  [padding-right length(in) / values]
+    expected: FAIL
+
+  [padding-top length(pt) / values]
+    expected: FAIL
+
+  [padding-top length(pc) / values]
+    expected: FAIL
+
+  [padding-top length(px) / values]
+    expected: FAIL
+
+  [padding-top length(em) / values]
+    expected: FAIL
+
+  [padding-top length(ex) / values]
+    expected: FAIL
+
+  [padding-top length(mm) / values]
+    expected: FAIL
+
+  [padding-top length(cm) / values]
+    expected: FAIL
+
+  [padding-top length(in) / values]
+    expected: FAIL
+
+  [margin-bottom length(pt) / values]
+    expected: FAIL
+
+  [margin-bottom length(pc) / values]
+    expected: FAIL
+
+  [margin-bottom length(px) / values]
+    expected: FAIL
+
+  [margin-bottom length(em) / values]
+    expected: FAIL
+
+  [margin-bottom length(ex) / values]
+    expected: FAIL
+
+  [margin-bottom length(mm) / values]
+    expected: FAIL
+
+  [margin-bottom length(cm) / values]
+    expected: FAIL
+
+  [margin-bottom length(in) / values]
+    expected: FAIL
+
+  [margin-left length(pt) / values]
+    expected: FAIL
+
+  [margin-left length(pc) / values]
+    expected: FAIL
+
+  [margin-left length(px) / values]
+    expected: FAIL
+
+  [margin-left length(em) / values]
+    expected: FAIL
+
+  [margin-left length(ex) / values]
+    expected: FAIL
+
+  [margin-left length(mm) / values]
+    expected: FAIL
+
+  [margin-left length(cm) / values]
+    expected: FAIL
+
+  [margin-left length(in) / values]
+    expected: FAIL
+
+  [margin-right length(pt) / values]
+    expected: FAIL
+
+  [margin-right length(pc) / values]
+    expected: FAIL
+
+  [margin-right length(px) / values]
+    expected: FAIL
+
+  [margin-right length(em) / values]
+    expected: FAIL
+
+  [margin-right length(ex) / values]
+    expected: FAIL
+
+  [margin-right length(mm) / values]
+    expected: FAIL
diff --git a/tests/wpt/metadata/css/css-transitions/properties-value-inherit-001.html.ini b/tests/wpt/metadata/css/css-transitions/properties-value-inherit-001.html.ini
index 03f4e0ef301..998682c8a35 100644
--- a/tests/wpt/metadata/css/css-transitions/properties-value-inherit-001.html.ini
+++ b/tests/wpt/metadata/css/css-transitions/properties-value-inherit-001.html.ini
@@ -205,3 +205,303 @@
 
   [margin-right length(mm) / events]
     expected: FAIL
+
+  [margin-right length(cm) / events]
+    expected: FAIL
+
+  [margin-right length(in) / events]
+    expected: FAIL
+
+  [margin-top length(pt) / events]
+    expected: FAIL
+
+  [margin-top length(pc) / events]
+    expected: FAIL
+
+  [margin-top length(px) / events]
+    expected: FAIL
+
+  [margin-top length(em) / events]
+    expected: FAIL
+
+  [margin-top length(ex) / events]
+    expected: FAIL
+
+  [margin-top length(mm) / events]
+    expected: FAIL
+
+  [margin-top length(cm) / events]
+    expected: FAIL
+
+  [margin-top length(in) / events]
+    expected: FAIL
+
+  [height length(pt) / events]
+    expected: FAIL
+
+  [height length(pc) / events]
+    expected: FAIL
+
+  [height length(px) / events]
+    expected: FAIL
+
+  [height length(em) / events]
+    expected: FAIL
+
+  [height length(ex) / events]
+    expected: FAIL
+
+  [height length(mm) / events]
+    expected: FAIL
+
+  [height length(cm) / events]
+    expected: FAIL
+
+  [height length(in) / events]
+    expected: FAIL
+
+  [height percentage(%) / events]
+    expected: FAIL
+
+  [width length(pt) / events]
+    expected: FAIL
+
+  [width length(pc) / events]
+    expected: FAIL
+
+  [width length(px) / events]
+    expected: FAIL
+
+  [width length(em) / events]
+    expected: FAIL
+
+  [width length(ex) / events]
+    expected: FAIL
+
+  [width length(mm) / events]
+    expected: FAIL
+
+  [width length(cm) / events]
+    expected: FAIL
+
+  [width length(in) / events]
+    expected: FAIL
+
+  [width percentage(%) / events]
+    expected: FAIL
+
+  [min-height length(pt) / events]
+    expected: FAIL
+
+  [min-height length(pc) / events]
+    expected: FAIL
+
+  [min-height length(px) / events]
+    expected: FAIL
+
+  [min-height length(em) / events]
+    expected: FAIL
+
+  [min-height length(ex) / events]
+    expected: FAIL
+
+  [min-height length(mm) / events]
+    expected: FAIL
+
+  [min-height length(cm) / events]
+    expected: FAIL
+
+  [min-height length(in) / events]
+    expected: FAIL
+
+  [min-height percentage(%) / events]
+    expected: FAIL
+
+  [min-width length(pt) / events]
+    expected: FAIL
+
+  [min-width length(pc) / events]
+    expected: FAIL
+
+  [min-width length(px) / events]
+    expected: FAIL
+
+  [min-width length(em) / events]
+    expected: FAIL
+
+  [min-width length(ex) / events]
+    expected: FAIL
+
+  [min-width length(mm) / events]
+    expected: FAIL
+
+  [min-width length(cm) / events]
+    expected: FAIL
+
+  [min-width length(in) / events]
+    expected: FAIL
+
+  [min-width percentage(%) / events]
+    expected: FAIL
+
+  [max-height length(pt) / events]
+    expected: FAIL
+
+  [max-height length(pc) / events]
+    expected: FAIL
+
+  [max-height length(px) / events]
+    expected: FAIL
+
+  [max-height length(em) / events]
+    expected: FAIL
+
+  [max-height length(ex) / events]
+    expected: FAIL
+
+  [max-height length(mm) / events]
+    expected: FAIL
+
+  [max-height length(cm) / events]
+    expected: FAIL
+
+  [max-height length(in) / events]
+    expected: FAIL
+
+  [max-height percentage(%) / events]
+    expected: FAIL
+
+  [max-width length(pt) / events]
+    expected: FAIL
+
+  [max-width length(pc) / events]
+    expected: FAIL
+
+  [max-width length(px) / events]
+    expected: FAIL
+
+  [max-width length(em) / events]
+    expected: FAIL
+
+  [max-width length(ex) / events]
+    expected: FAIL
+
+  [max-width length(mm) / events]
+    expected: FAIL
+
+  [max-width length(cm) / events]
+    expected: FAIL
+
+  [max-width length(in) / events]
+    expected: FAIL
+
+  [max-width percentage(%) / events]
+    expected: FAIL
+
+  [top length(pt) / events]
+    expected: FAIL
+
+  [top length(pc) / events]
+    expected: FAIL
+
+  [top length(px) / events]
+    expected: FAIL
+
+  [top length(em) / events]
+    expected: FAIL
+
+  [top length(ex) / events]
+    expected: FAIL
+
+  [top length(mm) / events]
+    expected: FAIL
+
+  [top length(cm) / events]
+    expected: FAIL
+
+  [top length(in) / events]
+    expected: FAIL
+
+  [top percentage(%) / events]
+    expected: FAIL
+
+  [right length(pt) / events]
+    expected: FAIL
+
+  [right length(pc) / events]
+    expected: FAIL
+
+  [right length(px) / events]
+    expected: FAIL
+
+  [right length(em) / events]
+    expected: FAIL
+
+  [right length(ex) / events]
+    expected: FAIL
+
+  [right length(mm) / events]
+    expected: FAIL
+
+  [right length(cm) / events]
+    expected: FAIL
+
+  [right length(in) / events]
+    expected: FAIL
+
+  [right percentage(%) / events]
+    expected: FAIL
+
+  [bottom length(pt) / events]
+    expected: FAIL
+
+  [bottom length(pc) / events]
+    expected: FAIL
+
+  [bottom length(px) / events]
+    expected: FAIL
+
+  [bottom length(em) / events]
+    expected: FAIL
+
+  [bottom length(ex) / events]
+    expected: FAIL
+
+  [bottom length(mm) / events]
+    expected: FAIL
+
+  [bottom length(cm) / events]
+    expected: FAIL
+
+  [bottom length(in) / events]
+    expected: FAIL
+
+  [bottom percentage(%) / events]
+    expected: FAIL
+
+  [left length(pt) / events]
+    expected: FAIL
+
+  [left length(pc) / events]
+    expected: FAIL
+
+  [left length(px) / events]
+    expected: FAIL
+
+  [left length(em) / events]
+    expected: FAIL
+
+  [left length(ex) / events]
+    expected: FAIL
+
+  [left length(mm) / events]
+    expected: FAIL
+
+  [left length(cm) / events]
+    expected: FAIL
+
+  [left length(in) / events]
+    expected: FAIL
+
+  [left percentage(%) / events]
+    expected: FAIL
diff --git a/tests/wpt/metadata/css/css-transitions/properties-value-inherit-002.html.ini b/tests/wpt/metadata/css/css-transitions/properties-value-inherit-002.html.ini
index 242ba44bbca..793afafa0e8 100644
--- a/tests/wpt/metadata/css/css-transitions/properties-value-inherit-002.html.ini
+++ b/tests/wpt/metadata/css/css-transitions/properties-value-inherit-002.html.ini
@@ -52,3 +52,276 @@
 
   [background-position length(px) / events]
     expected: FAIL
+
+  [background-color color(rgba) / values]
+    expected: FAIL
+
+  [border-top-width length(pt) / values]
+    expected: FAIL
+
+  [border-top-width length(pc) / values]
+    expected: FAIL
+
+  [border-top-width length(px) / values]
+    expected: FAIL
+
+  [border-top-width length(em) / values]
+    expected: FAIL
+
+  [border-top-width length(ex) / values]
+    expected: FAIL
+
+  [border-top-width length(mm) / values]
+    expected: FAIL
+
+  [border-top-width length(cm) / values]
+    expected: FAIL
+
+  [border-top-width length(in) / values]
+    expected: FAIL
+
+  [border-right-width length(pt) / values]
+    expected: FAIL
+
+  [border-right-width length(pc) / values]
+    expected: FAIL
+
+  [border-right-width length(px) / values]
+    expected: FAIL
+
+  [border-right-width length(em) / values]
+    expected: FAIL
+
+  [border-right-width length(ex) / values]
+    expected: FAIL
+
+  [border-right-width length(mm) / values]
+    expected: FAIL
+
+  [border-right-width length(cm) / values]
+    expected: FAIL
+
+  [border-right-width length(in) / values]
+    expected: FAIL
+
+  [border-bottom-width length(pt) / values]
+    expected: FAIL
+
+  [border-bottom-width length(pc) / values]
+    expected: FAIL
+
+  [border-bottom-width length(px) / values]
+    expected: FAIL
+
+  [border-bottom-width length(em) / values]
+    expected: FAIL
+
+  [border-bottom-width length(ex) / values]
+    expected: FAIL
+
+  [border-bottom-width length(mm) / values]
+    expected: FAIL
+
+  [border-bottom-width length(cm) / values]
+    expected: FAIL
+
+  [border-bottom-width length(in) / values]
+    expected: FAIL
+
+  [border-left-width length(pt) / values]
+    expected: FAIL
+
+  [border-left-width length(pc) / values]
+    expected: FAIL
+
+  [border-left-width length(px) / values]
+    expected: FAIL
+
+  [border-left-width length(em) / values]
+    expected: FAIL
+
+  [border-left-width length(ex) / values]
+    expected: FAIL
+
+  [border-left-width length(mm) / values]
+    expected: FAIL
+
+  [border-left-width length(cm) / values]
+    expected: FAIL
+
+  [border-left-width length(in) / values]
+    expected: FAIL
+
+  [border-top-color color(rgba) / values]
+    expected: FAIL
+
+  [border-right-color color(rgba) / values]
+    expected: FAIL
+
+  [border-bottom-color color(rgba) / values]
+    expected: FAIL
+
+  [border-left-color color(rgba) / values]
+    expected: FAIL
+
+  [padding-bottom length(pt) / values]
+    expected: FAIL
+
+  [padding-bottom length(pc) / values]
+    expected: FAIL
+
+  [padding-bottom length(px) / values]
+    expected: FAIL
+
+  [padding-bottom length(em) / values]
+    expected: FAIL
+
+  [color color(rgba) / values]
+    expected: FAIL
+
+  [font-size length(pt) / values]
+    expected: FAIL
+
+  [font-size length(pc) / values]
+    expected: FAIL
+
+  [font-size length(px) / values]
+    expected: FAIL
+
+  [font-size length(em) / values]
+    expected: FAIL
+
+  [font-size length(ex) / values]
+    expected: FAIL
+
+  [font-size length(mm) / values]
+    expected: FAIL
+
+  [font-size length(cm) / values]
+    expected: FAIL
+
+  [font-size length(in) / values]
+    expected: FAIL
+
+  [font-size percentage(%) / values]
+    expected: FAIL
+
+  [font-weight font-weight(keyword) / values]
+    expected: FAIL
+
+  [font-weight font-weight(numeric) / values]
+    expected: FAIL
+
+  [line-height number(integer) / values]
+    expected: FAIL
+
+  [line-height number(decimal) / values]
+    expected: FAIL
+
+  [line-height length(pt) / values]
+    expected: FAIL
+
+  [line-height length(pc) / values]
+    expected: FAIL
+
+  [line-height length(px) / values]
+    expected: FAIL
+
+  [line-height length(em) / values]
+    expected: FAIL
+
+  [line-height length(ex) / values]
+    expected: FAIL
+
+  [line-height length(mm) / values]
+    expected: FAIL
+
+  [line-height length(cm) / values]
+    expected: FAIL
+
+  [line-height length(in) / values]
+    expected: FAIL
+
+  [line-height percentage(%) / values]
+    expected: FAIL
+
+  [letter-spacing length(pt) / values]
+    expected: FAIL
+
+  [letter-spacing length(pc) / values]
+    expected: FAIL
+
+  [letter-spacing length(px) / values]
+    expected: FAIL
+
+  [letter-spacing length(em) / values]
+    expected: FAIL
+
+  [letter-spacing length(ex) / values]
+    expected: FAIL
+
+  [letter-spacing length(mm) / values]
+    expected: FAIL
+
+  [letter-spacing length(cm) / values]
+    expected: FAIL
+
+  [letter-spacing length(in) / values]
+    expected: FAIL
+
+  [word-spacing length(pt) / values]
+    expected: FAIL
+
+  [word-spacing length(pc) / values]
+    expected: FAIL
+
+  [word-spacing length(px) / values]
+    expected: FAIL
+
+  [word-spacing length(em) / values]
+    expected: FAIL
+
+  [word-spacing length(ex) / values]
+    expected: FAIL
+
+  [word-spacing length(mm) / values]
+    expected: FAIL
+
+  [word-spacing length(cm) / values]
+    expected: FAIL
+
+  [word-spacing length(in) / values]
+    expected: FAIL
+
+  [word-spacing percentage(%) / values]
+    expected: FAIL
+
+  [text-indent length(pt) / values]
+    expected: FAIL
+
+  [text-indent length(pc) / values]
+    expected: FAIL
+
+  [text-indent length(px) / values]
+    expected: FAIL
+
+  [text-indent length(em) / values]
+    expected: FAIL
+
+  [text-indent length(ex) / values]
+    expected: FAIL
+
+  [text-indent length(mm) / values]
+    expected: FAIL
+
+  [text-indent length(cm) / values]
+    expected: FAIL
+
+  [text-indent length(in) / values]
+    expected: FAIL
+
+  [text-indent percentage(%) / values]
+    expected: FAIL
+
+  [text-shadow shadow(shadow) / values]
+    expected: FAIL
diff --git a/tests/wpt/metadata/css/css-transitions/pseudo-elements-001.html.ini b/tests/wpt/metadata/css/css-transitions/pseudo-elements-001.html.ini
index f7867715155..27fb29a8075 100644
--- a/tests/wpt/metadata/css/css-transitions/pseudo-elements-001.html.ini
+++ b/tests/wpt/metadata/css/css-transitions/pseudo-elements-001.html.ini
@@ -4,9 +4,3 @@
 
   [transition padding-left on :after / values]
     expected: FAIL
-
-  [transition padding-left on :before, changing content / values]
-    expected: FAIL
-
-  [transition padding-left on :after, changing content / values]
-    expected: FAIL
diff --git a/tests/wpt/metadata/css/cssom-view/MediaQueryList-addListener-handleEvent.html.ini b/tests/wpt/metadata/css/cssom-view/MediaQueryList-addListener-handleEvent.html.ini
index 037d7e0f951..2869eb8616e 100644
--- a/tests/wpt/metadata/css/cssom-view/MediaQueryList-addListener-handleEvent.html.ini
+++ b/tests/wpt/metadata/css/cssom-view/MediaQueryList-addListener-handleEvent.html.ini
@@ -4,3 +4,6 @@
 
   [throws if handleEvent is thruthy and not callable]
     expected: FAIL
+
+  [calls handleEvent method of event listener]
+    expected: FAIL
diff --git a/tests/wpt/metadata/css/cssom-view/elementFromPoint-001.html.ini b/tests/wpt/metadata/css/cssom-view/elementFromPoint-001.html.ini
new file mode 100644
index 00000000000..72b09371038
--- /dev/null
+++ b/tests/wpt/metadata/css/cssom-view/elementFromPoint-001.html.ini
@@ -0,0 +1,3 @@
+[elementFromPoint-001.html]
+  [CSSOM View - 5 - extensions to the Document interface]
+    expected: FAIL
diff --git a/tests/wpt/metadata/css/cssom-view/elementFromPoint-dynamic-anon-box.html.ini b/tests/wpt/metadata/css/cssom-view/elementFromPoint-dynamic-anon-box.html.ini
new file mode 100644
index 00000000000..cf67b5d03dd
--- /dev/null
+++ b/tests/wpt/metadata/css/cssom-view/elementFromPoint-dynamic-anon-box.html.ini
@@ -0,0 +1,3 @@
+[elementFromPoint-dynamic-anon-box.html]
+  [Link should be clickable after hiding a scrollbox with an anonymous table inside]
+    expected: FAIL
diff --git a/tests/wpt/metadata/css/cssom-view/elementsFromPoint-invalid-cases.html.ini b/tests/wpt/metadata/css/cssom-view/elementsFromPoint-invalid-cases.html.ini
deleted file mode 100644
index a3496a40d07..00000000000
--- a/tests/wpt/metadata/css/cssom-view/elementsFromPoint-invalid-cases.html.ini
+++ /dev/null
@@ -1,3 +0,0 @@
-[elementsFromPoint-invalid-cases.html]
-  [The root element is the last element returned for otherwise empty queries within the viewport]
-    expected: FAIL
diff --git a/tests/wpt/metadata/css/cssom/CSSFontFeatureValuesRule.html.ini b/tests/wpt/metadata/css/cssom/CSSFontFeatureValuesRule.html.ini
index 601430b639c..e55d4bd51a2 100644
--- a/tests/wpt/metadata/css/cssom/CSSFontFeatureValuesRule.html.ini
+++ b/tests/wpt/metadata/css/cssom/CSSFontFeatureValuesRule.html.ini
@@ -19,3 +19,6 @@
 
   [Clearing all entries is possible.]
     expected: FAIL
+
+  [Multiple rules for the same family are kept separate in CSSOM.]
+    expected: FAIL
diff --git a/tests/wpt/metadata/fetch/content-length/parsing.window.js.ini b/tests/wpt/metadata/fetch/content-length/parsing.window.js.ini
index 3285a4f15ac..fc21a631bdd 100644
--- a/tests/wpt/metadata/fetch/content-length/parsing.window.js.ini
+++ b/tests/wpt/metadata/fetch/content-length/parsing.window.js.ini
@@ -76,3 +76,6 @@
 
   [Input: "Content-Length: ". Expected: 42.]
     expected: FAIL
+
+  [Input: "Content-Length: 30". Expected: 30.]
+    expected: FAIL
diff --git a/tests/wpt/metadata/fetch/content-type/response.window.js.ini b/tests/wpt/metadata/fetch/content-type/response.window.js.ini
index f5ba8274138..3a63b5ae7e7 100644
--- a/tests/wpt/metadata/fetch/content-type/response.window.js.ini
+++ b/tests/wpt/metadata/fetch/content-type/response.window.js.ini
@@ -308,3 +308,6 @@
 
   [fetch(): separate response Content-Type: text/plain ]
     expected: NOTRUN
+
+  [<iframe>: combined response Content-Type: text/html;charset=gbk text/plain text/html]
+    expected: FAIL
diff --git a/tests/wpt/metadata/fetch/metadata/generated/css-images.sub.tentative.html.ini b/tests/wpt/metadata/fetch/metadata/generated/css-images.sub.tentative.html.ini
index f9de5391ad6..9749a4fccd5 100644
--- a/tests/wpt/metadata/fetch/metadata/generated/css-images.sub.tentative.html.ini
+++ b/tests/wpt/metadata/fetch/metadata/generated/css-images.sub.tentative.html.ini
@@ -146,3 +146,6 @@
 
   [list-style-image sec-fetch-site - HTTPS downgrade-upgrade]
     expected: FAIL
+
+  [border-image sec-fetch-dest - Not sent to non-trustworthy cross-site destination]
+    expected: FAIL
diff --git a/tests/wpt/metadata/fetch/nosniff/parsing-nosniff.window.js.ini b/tests/wpt/metadata/fetch/nosniff/parsing-nosniff.window.js.ini
index 638a958a465..ba47e36f3af 100644
--- a/tests/wpt/metadata/fetch/nosniff/parsing-nosniff.window.js.ini
+++ b/tests/wpt/metadata/fetch/nosniff/parsing-nosniff.window.js.ini
@@ -8,11 +8,5 @@
   [X-Content-Type-Options%3A%20nosniff%0C]
     expected: FAIL
 
-  [X-Content-Type-Options%3A%20%40%23%24%23%25%25%26%5E%26%5E*()()11!%2Cnosniff]
-    expected: FAIL
-
-  [X-Content-Type-Options%3A%20no%0D%0AX-Content-Type-Options%3A%20nosniff]
-    expected: FAIL
-
   [X-Content-Type-Options%3A%20%2Cnosniff]
     expected: FAIL
diff --git a/tests/wpt/metadata/html/browsers/browsing-the-web/navigating-across-documents/005.html.ini b/tests/wpt/metadata/html/browsers/browsing-the-web/navigating-across-documents/005.html.ini
index f7ee5361549..33efcdbcf48 100644
--- a/tests/wpt/metadata/html/browsers/browsing-the-web/navigating-across-documents/005.html.ini
+++ b/tests/wpt/metadata/html/browsers/browsing-the-web/navigating-across-documents/005.html.ini
@@ -1,4 +1,3 @@
 [005.html]
-  expected: TIMEOUT
   [Link with onclick navigation and href navigation ]
     expected: FAIL
diff --git a/tests/wpt/metadata/html/browsers/browsing-the-web/navigating-across-documents/initial-empty-document/load-pageshow-events-iframe-contentWindow.html.ini b/tests/wpt/metadata/html/browsers/browsing-the-web/navigating-across-documents/initial-empty-document/load-pageshow-events-iframe-contentWindow.html.ini
index 149bcb4ff8c..51fd557bd7f 100644
--- a/tests/wpt/metadata/html/browsers/browsing-the-web/navigating-across-documents/initial-empty-document/load-pageshow-events-iframe-contentWindow.html.ini
+++ b/tests/wpt/metadata/html/browsers/browsing-the-web/navigating-across-documents/initial-empty-document/load-pageshow-events-iframe-contentWindow.html.ini
@@ -7,6 +7,3 @@
 
   [load & pageshow events do not fire on contentWindow of <iframe> element created with src='about:blank#foo']
     expected: FAIL
-
-  [load & pageshow events do not fire on contentWindow of <iframe> element created with src='about:blank']
-    expected: FAIL
diff --git a/tests/wpt/metadata/html/browsers/browsing-the-web/navigating-across-documents/javascript-url-no-beforeunload.window.js.ini b/tests/wpt/metadata/html/browsers/browsing-the-web/navigating-across-documents/javascript-url-no-beforeunload.window.js.ini
index 4b25ec32301..a06984505e9 100644
--- a/tests/wpt/metadata/html/browsers/browsing-the-web/navigating-across-documents/javascript-url-no-beforeunload.window.js.ini
+++ b/tests/wpt/metadata/html/browsers/browsing-the-web/navigating-across-documents/javascript-url-no-beforeunload.window.js.ini
@@ -5,3 +5,6 @@
 
   [Navigating an opened window via location.href to a javascript: URL must not fire beforeunload: string completion]
     expected: TIMEOUT
+
+  [Navigating an opened window with an iframe via location.href to a javascript: URL must not fire beforeunload on the iframe: undefined completion]
+    expected: FAIL
diff --git a/tests/wpt/metadata/html/browsers/browsing-the-web/navigating-across-documents/javascript-url-return-value-handling-dynamic.html.ini b/tests/wpt/metadata/html/browsers/browsing-the-web/navigating-across-documents/javascript-url-return-value-handling-dynamic.html.ini
index 8ae58f9f1e2..78240a2f463 100644
--- a/tests/wpt/metadata/html/browsers/browsing-the-web/navigating-across-documents/javascript-url-return-value-handling-dynamic.html.ini
+++ b/tests/wpt/metadata/html/browsers/browsing-the-web/navigating-across-documents/javascript-url-return-value-handling-dynamic.html.ini
@@ -16,6 +16,3 @@
 
   [D83D DE0D set in href="" targeting a frame and clicked]
     expected: FAIL
-
-  [DE0D 0041 set in href="" targeting a frame and clicked]
-    expected: FAIL
diff --git a/tests/wpt/metadata/html/browsers/browsing-the-web/navigating-across-documents/navigation-unload-cross-origin.sub.window.js.ini b/tests/wpt/metadata/html/browsers/browsing-the-web/navigating-across-documents/navigation-unload-cross-origin.sub.window.js.ini
deleted file mode 100644
index 4ecd6d9f753..00000000000
--- a/tests/wpt/metadata/html/browsers/browsing-the-web/navigating-across-documents/navigation-unload-cross-origin.sub.window.js.ini
+++ /dev/null
@@ -1,3 +0,0 @@
-[navigation-unload-cross-origin.sub.window.html]
-  [Cross-origin navigation started from unload handler must be ignored]
-    expected: FAIL
diff --git a/tests/wpt/metadata/html/browsers/browsing-the-web/navigating-across-documents/navigation-unload-same-origin.window.js.ini b/tests/wpt/metadata/html/browsers/browsing-the-web/navigating-across-documents/navigation-unload-same-origin.window.js.ini
new file mode 100644
index 00000000000..7dc346632a4
--- /dev/null
+++ b/tests/wpt/metadata/html/browsers/browsing-the-web/navigating-across-documents/navigation-unload-same-origin.window.js.ini
@@ -0,0 +1,3 @@
+[navigation-unload-same-origin.window.html]
+  [Same-origin navigation started from unload handler must be ignored]
+    expected: FAIL
diff --git a/tests/wpt/metadata/html/browsers/browsing-the-web/navigating-across-documents/replace-before-load/form-submit.html.ini b/tests/wpt/metadata/html/browsers/browsing-the-web/navigating-across-documents/replace-before-load/form-submit.html.ini
index f18f914e4a4..16371ab858d 100644
--- a/tests/wpt/metadata/html/browsers/browsing-the-web/navigating-across-documents/replace-before-load/form-submit.html.ini
+++ b/tests/wpt/metadata/html/browsers/browsing-the-web/navigating-across-documents/replace-before-load/form-submit.html.ini
@@ -1,3 +1,4 @@
 [form-submit.html]
+  expected: TIMEOUT
   [Replace before load, triggered by formElement.submit()]
-    expected: FAIL
+    expected: TIMEOUT
diff --git a/tests/wpt/metadata/html/browsers/history/the-history-interface/traverse-during-unload.html.ini b/tests/wpt/metadata/html/browsers/history/the-history-interface/traverse-during-unload.html.ini
new file mode 100644
index 00000000000..f5b7b25324f
--- /dev/null
+++ b/tests/wpt/metadata/html/browsers/history/the-history-interface/traverse-during-unload.html.ini
@@ -0,0 +1,4 @@
+[traverse-during-unload.html]
+  expected: TIMEOUT
+  [Traversing the history during unload]
+    expected: TIMEOUT
diff --git a/tests/wpt/metadata/html/semantics/embedded-content/the-iframe-element/sandbox-top-navigation-child-special-cases.tentative.sub.window.js.ini b/tests/wpt/metadata/html/semantics/embedded-content/the-iframe-element/sandbox-top-navigation-child-special-cases.tentative.sub.window.js.ini
index 31745fdcdcf..31928ad3947 100644
--- a/tests/wpt/metadata/html/semantics/embedded-content/the-iframe-element/sandbox-top-navigation-child-special-cases.tentative.sub.window.js.ini
+++ b/tests/wpt/metadata/html/semantics/embedded-content/the-iframe-element/sandbox-top-navigation-child-special-cases.tentative.sub.window.js.ini
@@ -1,4 +1,5 @@
 [sandbox-top-navigation-child-special-cases.tentative.sub.window.html]
+  expected: TIMEOUT
   [Allow top with user activation + user activation]
     expected: FAIL
 
diff --git a/tests/wpt/metadata/html/semantics/forms/historical.html.ini b/tests/wpt/metadata/html/semantics/forms/historical.html.ini
new file mode 100644
index 00000000000..5d8289307cc
--- /dev/null
+++ b/tests/wpt/metadata/html/semantics/forms/historical.html.ini
@@ -0,0 +1,3 @@
+[historical.html]
+  [<input name=isindex> should not be supported]
+    expected: FAIL
diff --git a/tests/wpt/metadata/html/semantics/links/links-created-by-a-and-area-elements/htmlanchorelement_noopener.html.ini b/tests/wpt/metadata/html/semantics/links/links-created-by-a-and-area-elements/htmlanchorelement_noopener.html.ini
index cc18f512574..73807cb3cc1 100644
--- a/tests/wpt/metadata/html/semantics/links/links-created-by-a-and-area-elements/htmlanchorelement_noopener.html.ini
+++ b/tests/wpt/metadata/html/semantics/links/links-created-by-a-and-area-elements/htmlanchorelement_noopener.html.ini
@@ -1,5 +1,6 @@
 [htmlanchorelement_noopener.html]
   type: testharness
+  expected: TIMEOUT
   [Check that targeting of rel=noopener with a given name ignores an existing window with that name]
     expected: NOTRUN
 
@@ -13,4 +14,4 @@
     expected: FAIL
 
   [Check that rel=noopener with target=_self does a normal load]
-    expected: FAIL
+    expected: NOTRUN
diff --git a/tests/wpt/metadata/html/semantics/scripting-1/the-script-element/defer-script/async-script.html.ini b/tests/wpt/metadata/html/semantics/scripting-1/the-script-element/defer-script/async-script.html.ini
new file mode 100644
index 00000000000..1181798bd79
--- /dev/null
+++ b/tests/wpt/metadata/html/semantics/scripting-1/the-script-element/defer-script/async-script.html.ini
@@ -0,0 +1,4 @@
+[async-script.html]
+
+[async-script.html?reload]
+  expected: ERROR
diff --git a/tests/wpt/metadata/html/syntax/parsing/DOMContentLoaded-defer.html.ini b/tests/wpt/metadata/html/syntax/parsing/DOMContentLoaded-defer.html.ini
new file mode 100644
index 00000000000..b8bdf33cb65
--- /dev/null
+++ b/tests/wpt/metadata/html/syntax/parsing/DOMContentLoaded-defer.html.ini
@@ -0,0 +1,3 @@
+[DOMContentLoaded-defer.html]
+  [The end: DOMContentLoaded and defer scripts]
+    expected: FAIL
diff --git a/tests/wpt/metadata/html/webappapis/scripting/processing-model-2/integration-with-the-javascript-job-queue/promise-job-entry-different-function-realm.html.ini b/tests/wpt/metadata/html/webappapis/scripting/processing-model-2/integration-with-the-javascript-job-queue/promise-job-entry-different-function-realm.html.ini
index 7237f5792de..dbe1def99e3 100644
--- a/tests/wpt/metadata/html/webappapis/scripting/processing-model-2/integration-with-the-javascript-job-queue/promise-job-entry-different-function-realm.html.ini
+++ b/tests/wpt/metadata/html/webappapis/scripting/processing-model-2/integration-with-the-javascript-job-queue/promise-job-entry-different-function-realm.html.ini
@@ -1,10 +1,9 @@
 [promise-job-entry-different-function-realm.html]
-  expected: TIMEOUT
   [Fulfillment handler on fulfilled promise]
     expected: FAIL
 
   [Rejection handler on pending-then-rejected promise]
-    expected: TIMEOUT
+    expected: FAIL
 
   [Thenable resolution]
     expected: FAIL
@@ -13,4 +12,4 @@
     expected: FAIL
 
   [Fulfillment handler on pending-then-fulfilled promise]
-    expected: TIMEOUT
+    expected: FAIL
diff --git a/tests/wpt/metadata/performance-timeline/tentative/include-frames-from-child-cross-origin-grandchild.sub.html.ini b/tests/wpt/metadata/performance-timeline/tentative/include-frames-from-child-cross-origin-grandchild.sub.html.ini
new file mode 100644
index 00000000000..7110841423a
--- /dev/null
+++ b/tests/wpt/metadata/performance-timeline/tentative/include-frames-from-child-cross-origin-grandchild.sub.html.ini
@@ -0,0 +1,4 @@
+[include-frames-from-child-cross-origin-grandchild.sub.html]
+  expected: ERROR
+  [GetEntries of a Cross-Origin child frame with one Cross-Origin grandchild frame]
+    expected: TIMEOUT
diff --git a/tests/wpt/metadata/performance-timeline/tentative/include-frames-from-child-same-origin-grandchild.sub.html.ini b/tests/wpt/metadata/performance-timeline/tentative/include-frames-from-child-same-origin-grandchild.sub.html.ini
new file mode 100644
index 00000000000..5498d923404
--- /dev/null
+++ b/tests/wpt/metadata/performance-timeline/tentative/include-frames-from-child-same-origin-grandchild.sub.html.ini
@@ -0,0 +1,4 @@
+[include-frames-from-child-same-origin-grandchild.sub.html]
+  expected: ERROR
+  [GetEntries of a Cross-Origin child frame with one Same-Origin grandchild frame]
+    expected: TIMEOUT
diff --git a/tests/wpt/metadata/performance-timeline/tentative/include-frames-one-cross-origin-child-one-same-origin-grandchild.sub.html.ini b/tests/wpt/metadata/performance-timeline/tentative/include-frames-one-cross-origin-child-one-same-origin-grandchild.sub.html.ini
new file mode 100644
index 00000000000..1b028f5c0ed
--- /dev/null
+++ b/tests/wpt/metadata/performance-timeline/tentative/include-frames-one-cross-origin-child-one-same-origin-grandchild.sub.html.ini
@@ -0,0 +1,4 @@
+[include-frames-one-cross-origin-child-one-same-origin-grandchild.sub.html]
+  expected: ERROR
+  [GetEntries of a parent Frame with one Cross-Origin child and one Same-Origin grandchild]
+    expected: TIMEOUT
diff --git a/tests/wpt/metadata/performance-timeline/tentative/include-frames-one-local-child-one-local-grandchild.html.ini b/tests/wpt/metadata/performance-timeline/tentative/include-frames-one-local-child-one-local-grandchild.html.ini
deleted file mode 100644
index 4e0e6da5670..00000000000
--- a/tests/wpt/metadata/performance-timeline/tentative/include-frames-one-local-child-one-local-grandchild.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[include-frames-one-local-child-one-local-grandchild.html]
-  expected: ERROR
-  [GetEntries of a ParentFrame with one LocalFrame child and one LocalFrame grandchild]
-    expected: TIMEOUT
diff --git a/tests/wpt/metadata/performance-timeline/tentative/include-frames-one-local-child-one-remote-child.sub.html.ini b/tests/wpt/metadata/performance-timeline/tentative/include-frames-one-local-child-one-remote-child.sub.html.ini
deleted file mode 100644
index bd067a13aee..00000000000
--- a/tests/wpt/metadata/performance-timeline/tentative/include-frames-one-local-child-one-remote-child.sub.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[include-frames-one-local-child-one-remote-child.sub.html]
-  expected: ERROR
-  [GetEntries of a ParentFrame with one RemoteFrame child and one LocalFrame child]
-    expected: TIMEOUT
diff --git a/tests/wpt/metadata/performance-timeline/tentative/include-frames-one-local-child.html.ini b/tests/wpt/metadata/performance-timeline/tentative/include-frames-one-local-child.html.ini
deleted file mode 100644
index 06390bd4d74..00000000000
--- a/tests/wpt/metadata/performance-timeline/tentative/include-frames-one-local-child.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[include-frames-one-local-child.html]
-  expected: ERROR
-  [GetEntries of a Parent Frame with one LocalFrame child]
-    expected: TIMEOUT
diff --git a/tests/wpt/metadata/performance-timeline/tentative/include-frames-one-remote-child-one-local-grandchild.sub.html.ini b/tests/wpt/metadata/performance-timeline/tentative/include-frames-one-remote-child-one-local-grandchild.sub.html.ini
deleted file mode 100644
index d972b27a9f6..00000000000
--- a/tests/wpt/metadata/performance-timeline/tentative/include-frames-one-remote-child-one-local-grandchild.sub.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[include-frames-one-remote-child-one-local-grandchild.sub.html]
-  expected: ERROR
-  [GetEntries of a ParentFrame with one RemoteFrame child and one LocalFrame grandchild]
-    expected: TIMEOUT
diff --git a/tests/wpt/metadata/performance-timeline/tentative/include-frames-one-same-origin-child-one-cross-origin-child.sub.html.ini b/tests/wpt/metadata/performance-timeline/tentative/include-frames-one-same-origin-child-one-cross-origin-child.sub.html.ini
new file mode 100644
index 00000000000..93df402e622
--- /dev/null
+++ b/tests/wpt/metadata/performance-timeline/tentative/include-frames-one-same-origin-child-one-cross-origin-child.sub.html.ini
@@ -0,0 +1,4 @@
+[include-frames-one-same-origin-child-one-cross-origin-child.sub.html]
+  expected: ERROR
+  [GetEntries of a parent Frame with one Cross-Origin child and one Same-Origin child]
+    expected: TIMEOUT
diff --git a/tests/wpt/metadata/performance-timeline/tentative/include-frames-one-same-origin-child-one-same-origin-grandchild.html.ini b/tests/wpt/metadata/performance-timeline/tentative/include-frames-one-same-origin-child-one-same-origin-grandchild.html.ini
new file mode 100644
index 00000000000..3c36bd59d1e
--- /dev/null
+++ b/tests/wpt/metadata/performance-timeline/tentative/include-frames-one-same-origin-child-one-same-origin-grandchild.html.ini
@@ -0,0 +1,4 @@
+[include-frames-one-same-origin-child-one-same-origin-grandchild.html]
+  expected: ERROR
+  [GetEntries of a parent Frame with one Same-Origin child and one Same-Origin grandchild]
+    expected: TIMEOUT
diff --git a/tests/wpt/metadata/performance-timeline/tentative/include-frames-one-same-origin-child.html.ini b/tests/wpt/metadata/performance-timeline/tentative/include-frames-one-same-origin-child.html.ini
new file mode 100644
index 00000000000..119a48720c4
--- /dev/null
+++ b/tests/wpt/metadata/performance-timeline/tentative/include-frames-one-same-origin-child.html.ini
@@ -0,0 +1,4 @@
+[include-frames-one-same-origin-child.html]
+  expected: ERROR
+  [GetEntries of a parent Frame with one Same-Origin child]
+    expected: TIMEOUT
diff --git a/tests/wpt/metadata/performance-timeline/tentative/include-frames-two-local-children.html.ini b/tests/wpt/metadata/performance-timeline/tentative/include-frames-two-local-children.html.ini
index 07fe4a75842..6eac8af1588 100644
--- a/tests/wpt/metadata/performance-timeline/tentative/include-frames-two-local-children.html.ini
+++ b/tests/wpt/metadata/performance-timeline/tentative/include-frames-two-local-children.html.ini
@@ -2,3 +2,6 @@
   expected: ERROR
   [GetEntries of a Parent Frame with two LocalFrame children]
     expected: TIMEOUT
+
+  [GetEntries of a parent Frame with two Same-Origin children]
+    expected: TIMEOUT
diff --git a/tests/wpt/metadata/performance-timeline/tentative/performance-entry-source.html.ini b/tests/wpt/metadata/performance-timeline/tentative/performance-entry-source.html.ini
new file mode 100644
index 00000000000..6d6c3f0fe97
--- /dev/null
+++ b/tests/wpt/metadata/performance-timeline/tentative/performance-entry-source.html.ini
@@ -0,0 +1,3 @@
+[performance-entry-source.html]
+  [PerformanceEntry source is equal to its respective Window]
+    expected: FAIL
diff --git a/tests/wpt/metadata/resource-timing/content-type-parsing.html.ini b/tests/wpt/metadata/resource-timing/content-type-parsing.html.ini
index 9f35c09a4a7..dea574899ad 100644
--- a/tests/wpt/metadata/resource-timing/content-type-parsing.html.ini
+++ b/tests/wpt/metadata/resource-timing/content-type-parsing.html.ini
@@ -25,40 +25,40 @@
     expected: FAIL
 
   [content-type 8 : text/plain;charset=gbk;x=foo,text/plain]
-    expected: TIMEOUT
+    expected: FAIL
 
   [content-type 9 : text/html;charset=gbk,text/plain,text/html]
-    expected: NOTRUN
+    expected: FAIL
 
   [content-type 10 : text/plain,*/*]
-    expected: NOTRUN
+    expected: FAIL
 
   [content-type 11 : text/html,*/*]
-    expected: NOTRUN
+    expected: FAIL
 
   [content-type 12 : */*,text/html]
-    expected: NOTRUN
+    expected: FAIL
 
   [content-type 13 : text/plain,*/*;charset=gbk]
-    expected: NOTRUN
+    expected: FAIL
 
   [content-type 14 : text/html,*/*;charset=gbk]
-    expected: NOTRUN
+    expected: FAIL
 
   [content-type 15 : text/html;x=",text/plain]
-    expected: NOTRUN
+    expected: FAIL
 
   [content-type 16 : text/html;",text/plain]
-    expected: NOTRUN
+    expected: FAIL
 
   [content-type 17 : text/html;",\\",text/plain]
-    expected: NOTRUN
+    expected: FAIL
 
   [content-type 18 : text/html;",\\",text/plain,";charset=GBK]
-    expected: NOTRUN
+    expected: FAIL
 
   [content-type 19 : text/html;",",text/plain]
-    expected: NOTRUN
+    expected: FAIL
 
   [mime-type 1 : text/html;charset=gbk]
     expected: NOTRUN
diff --git a/tests/wpt/metadata/webmessaging/broadcastchannel/cross-partition.https.tentative.html.ini b/tests/wpt/metadata/webmessaging/broadcastchannel/cross-partition.https.tentative.html.ini
index 39d039a0132..04c2032c723 100644
--- a/tests/wpt/metadata/webmessaging/broadcastchannel/cross-partition.https.tentative.html.ini
+++ b/tests/wpt/metadata/webmessaging/broadcastchannel/cross-partition.https.tentative.html.ini
@@ -1,5 +1,5 @@
 [cross-partition.https.tentative.html]
-  expected: CRASH
+  expected: TIMEOUT
   [BroadcastChannel messages aren't received from a cross-partition iframe]
     expected: FAIL
 
diff --git a/tests/wpt/metadata/webmessaging/with-ports/018.html.ini b/tests/wpt/metadata/webmessaging/with-ports/018.html.ini
deleted file mode 100644
index b7b36c1d3a4..00000000000
--- a/tests/wpt/metadata/webmessaging/with-ports/018.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[018.html]
-  expected: TIMEOUT
-  [origin of the script that invoked the method, javascript:]
-    expected: TIMEOUT
diff --git a/tests/wpt/metadata/webmessaging/without-ports/017.html.ini b/tests/wpt/metadata/webmessaging/without-ports/017.html.ini
deleted file mode 100644
index c7946fc91b4..00000000000
--- a/tests/wpt/metadata/webmessaging/without-ports/017.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[017.html]
-  expected: TIMEOUT
-  [origin of the script that invoked the method, about:blank]
-    expected: TIMEOUT
diff --git a/tests/wpt/web-platform-tests/content-security-policy/generic/invalid-characters-in-policy.html b/tests/wpt/web-platform-tests/content-security-policy/generic/invalid-characters-in-policy.html
index bd884c6fbd1..e46449117f6 100644
--- a/tests/wpt/web-platform-tests/content-security-policy/generic/invalid-characters-in-policy.html
+++ b/tests/wpt/web-platform-tests/content-security-policy/generic/invalid-characters-in-policy.html
@@ -25,6 +25,11 @@
         "expected": true,
         "name": "Non-ASCII character in directive value should drop the whole directive.",
       },
+      {
+        "csp": "img-src ‘none’;",
+        "expected": true,
+        "name": "Non-ASCII quote character in directive value should drop the whole directive.",
+      },
       {
         "csp": "img-src 'none'; style-src \u00A1invalid-source 'none'",
         "expected": false,
diff --git a/tests/wpt/web-platform-tests/css/css-animations/missing-values-first-keyframe.html b/tests/wpt/web-platform-tests/css/css-animations/missing-values-first-keyframe.html
new file mode 100644
index 00000000000..311e26259c7
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-animations/missing-values-first-keyframe.html
@@ -0,0 +1,84 @@
+<!DOCTYPE html>
+<html>
+<title>Missing properties in first keyframe</title>
+<meta name="viewport" content="width=device-width,initial-scale=1,minimum-scale=1">
+<link rel="help" href="https://www.w3.org/TR/web-animations-1/#the-effect-value-of-a-keyframe-animation-effect">
+<meta name="assert"
+      content="CSS animation correctly interpolates from neutral keyframe">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/web-animations/testcommon.js"></script>
+<style type="text/css" media="screen">
+  body {
+    margin: 0;
+  }
+
+  .box {
+    position: relative;
+    width: 100px;
+    height: 100px;
+    left: 0;
+    background-color: green;
+  }
+
+  #box1 {
+    left: 200px;
+    animation: move-left 2s paused linear;
+  }
+
+  #box2 {
+    transform: translateX(200px);
+    animation: move-transform 2s paused linear;
+  }
+
+  @keyframes move-left {
+    0% {
+      opacity: 1;
+    }
+    25% {
+      opacity: 1;
+    }
+    50% {
+      left: 0;
+      opacity: 1;
+    }
+    100% {
+      left: 0;
+      opacity: 0;
+    }
+  }
+
+  @keyframes move-transform {
+    0% {
+      opacity: 1;
+    }
+    25% {
+      opacity: 1;
+    }
+    50% {
+      transform: translateX(0);
+      opacity: 1;
+    }
+    100% {
+      transform: translateX(0);
+      opacity: 0;
+    }
+  }
+</style>
+<body>
+  <div class="box" id="box1"></div>
+  <div class="box" id="box2"></div>
+</body>
+<script>
+  promise_test(async t => {
+    document.getAnimations().forEach(anim => {
+      anim.currentTime = 500;
+    });
+    assert_equals(getComputedStyle(box1).left, "100px");
+    assert_matrix_equals(
+        getComputedStyle(box2).transform,
+        'matrix(1, 0, 0, 1, 100, 0)');
+  }, 'Missing property values in the first keyframe are correctly ' +
+     'interpolated from a neutral keyframe value');
+</script>
+</html>
diff --git a/tests/wpt/web-platform-tests/css/css-animations/missing-values-last-keyframe.html b/tests/wpt/web-platform-tests/css/css-animations/missing-values-last-keyframe.html
new file mode 100644
index 00000000000..04c4eba45e4
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-animations/missing-values-last-keyframe.html
@@ -0,0 +1,84 @@
+<!DOCTYPE html>
+<html>
+<title>Missing properties in last keyframe</title>
+<meta name="viewport" content="width=device-width,initial-scale=1,minimum-scale=1">
+<link rel="help" href="https://www.w3.org/TR/web-animations-1/#the-effect-value-of-a-keyframe-animation-effect">
+<meta name="assert"
+      content="CSS animation correctly interpolates from neutral keyframe">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/web-animations/testcommon.js"></script>
+<style type="text/css" media="screen">
+  body {
+    margin: 0;
+  }
+
+  .box {
+    position: relative;
+    width: 100px;
+    height: 100px;
+    left: 0;
+    background-color: green;
+  }
+
+  #box1 {
+    left: 200px;
+    animation: move-left 10s linear;
+  }
+
+  #box2 {
+    transform: translateX(200px);
+    animation: move-transform 10s linear;
+  }
+
+  @keyframes move-left {
+    0% {
+      left: 0;
+      opacity: 0;
+    }
+    50% {
+      left: 0;
+      opacity: 1;
+    }
+    75% {
+      opacity: 1;
+    }
+    100% {
+      opacity: 1;
+    }
+  }
+
+  @keyframes move-transform {
+    0% {
+      transform: translateX(0);
+      opacity: 0;
+    }
+    50% {
+      transform: translateX(0);
+      opacity: 1;
+    }
+    75% {
+      opacity: 1;
+    }
+    100% {
+      opacity: 1;
+    }
+  }
+</style>
+<body>
+  <div class="box" id="box1"></div>
+  <div class="box" id="box2"></div>
+</body>
+<script>
+  promise_test(async t => {
+    document.getAnimations().forEach(anim => {
+      anim.currentTime = 7500;
+    });
+    assert_equals(getComputedStyle(box1).left, "100px");
+    assert_matrix_equals(
+        getComputedStyle(box2).transform,
+        'matrix(1, 0, 0, 1, 100, 0)');
+  }, 'Missing property values in the last keyframe are correctly ' +
+     'interpolated from a neutral keyframe value');
+</script>
+</html>
diff --git a/tests/wpt/web-platform-tests/css/css-box/inheritance.html b/tests/wpt/web-platform-tests/css/css-box/inheritance.html
index d18106faf69..bf10aeeb8e0 100644
--- a/tests/wpt/web-platform-tests/css/css-box/inheritance.html
+++ b/tests/wpt/web-platform-tests/css/css-box/inheritance.html
@@ -23,7 +23,7 @@ assert_not_inherited('margin-bottom', '0px', '10px');
 assert_not_inherited('margin-left', '0px', '10px');
 assert_not_inherited('margin-right', '0px', '10px');
 assert_not_inherited('margin-top', '0px', '10px');
-assert_not_inherited('margin-trim', 'none', 'all');
+assert_not_inherited('margin-trim', 'none', 'block');
 assert_not_inherited('padding-bottom', '0px', '10px');
 assert_not_inherited('padding-left', '0px', '10px');
 assert_not_inherited('padding-right', '0px', '10px');
diff --git a/tests/wpt/web-platform-tests/css/css-break/grid/grid-item-placement-crash.html b/tests/wpt/web-platform-tests/css/css-break/grid/grid-item-placement-crash.html
new file mode 100644
index 00000000000..e6cc6c8b519
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-break/grid/grid-item-placement-crash.html
@@ -0,0 +1,17 @@
+<!DOCTYPE html>
+<link rel="help" href="https://bugs.chromium.org/p/chromium/issues/detail?id=1399336">
+<body>
+  <div style="width: 2000px; height: 2000px;">
+    <div style="columns: 2; border: 1px solid black;">
+      <div style="height: 50px; width: 550px; float: right;">Text</div>
+      <div style="display: grid; grid-template-columns: repeat(auto-fill,250px);">
+        <div style="width: 250px;">
+          <div style="height: 550px;"></div>
+        </div>
+        <div style="width: 250px;">
+          <div style="height: 550px;"></div>
+        </div>
+      </div>
+    </div>
+  </div>
+</body>
diff --git a/tests/wpt/web-platform-tests/css/css-break/out-of-flow-in-multicolumn-100.html b/tests/wpt/web-platform-tests/css/css-break/out-of-flow-in-multicolumn-100.html
new file mode 100644
index 00000000000..1bf71e832de
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-break/out-of-flow-in-multicolumn-100.html
@@ -0,0 +1,13 @@
+<!DOCTYPE html>
+<link rel="author" title="Morten Stenshorne" href="mailto:mstensho@chromium.org">
+<link rel="help" href="https://bugs.chromium.org/p/chromium/issues/detail?id=1395581">
+<link rel="match" href="../reference/ref-filled-green-100px-square.xht">
+<p>Test passes if there is a filled green square and <strong>no red</strong>.</p>
+<div style="columns:2; column-fill:auto; height:200px;">
+  <div style="width:60px; height:60px; direction:rtl; border:20px solid green; background:red;">
+    <div style="position:relative;">
+      <div style="position:absolute; left:0; top:0; width:60px; height:30px; background:green;"></div>
+      <div style="position:absolute; right:0; top:30px; width:60px; height:30px; background:green;"></div>
+    </div>
+  </div>
+</div>
diff --git a/tests/wpt/web-platform-tests/css/css-break/out-of-flow-in-multicolumn-101.html b/tests/wpt/web-platform-tests/css/css-break/out-of-flow-in-multicolumn-101.html
new file mode 100644
index 00000000000..ed7e1e234d8
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-break/out-of-flow-in-multicolumn-101.html
@@ -0,0 +1,13 @@
+<!DOCTYPE html>
+<link rel="author" title="Morten Stenshorne" href="mailto:mstensho@chromium.org">
+<link rel="help" href="https://bugs.chromium.org/p/chromium/issues/detail?id=1395581">
+<link rel="match" href="../reference/ref-filled-green-100px-square.xht">
+<p>Test passes if there is a filled green square and <strong>no red</strong>.</p>
+<div style="columns:2; column-fill:auto; gap:0; width:100px; height:100px; background:red;">
+  <div style="width:30px; height:180px; direction:rtl; border:10px solid green;">
+    <div style="position:relative;">
+      <div style="position:absolute; left:0; top:0; width:30px; height:90px; background:green;"></div>
+      <div style="position:absolute; right:0; top:90px; width:30px; height:90px; background:green;"></div>
+    </div>
+  </div>
+</div>
diff --git a/tests/wpt/web-platform-tests/css/css-break/out-of-flow-in-multicolumn-102.html b/tests/wpt/web-platform-tests/css/css-break/out-of-flow-in-multicolumn-102.html
new file mode 100644
index 00000000000..45cbc0b4533
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-break/out-of-flow-in-multicolumn-102.html
@@ -0,0 +1,13 @@
+<!DOCTYPE html>
+<link rel="author" title="Morten Stenshorne" href="mailto:mstensho@chromium.org">
+<link rel="help" href="https://bugs.chromium.org/p/chromium/issues/detail?id=1395581">
+<link rel="match" href="../reference/ref-filled-green-100px-square.xht">
+<p>Test passes if there is a filled green square and <strong>no red</strong>.</p>
+<div style="position:absolute; margin-left:15px; margin-top:15px; width:30px; height:70px; background:green;"></div>
+<div style="columns:2; column-fill:auto; height:200px;">
+  <div style="width:70px; height:70px; direction:rtl; border:solid 15px green; background:red;">
+    <div style="position:relative;">
+      <div style="position:absolute; width:40px; height:70px; background:green;"></div>
+    </div>
+  </div>
+</div>
diff --git a/tests/wpt/web-platform-tests/css/css-break/out-of-flow-in-multicolumn-103.html b/tests/wpt/web-platform-tests/css/css-break/out-of-flow-in-multicolumn-103.html
new file mode 100644
index 00000000000..b54cbcd85a8
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-break/out-of-flow-in-multicolumn-103.html
@@ -0,0 +1,14 @@
+<!DOCTYPE html>
+<link rel="author" title="Morten Stenshorne" href="mailto:mstensho@chromium.org">
+<link rel="help" href="https://bugs.chromium.org/p/chromium/issues/detail?id=1395581">
+<link rel="match" href="../reference/ref-filled-green-100px-square.xht">
+<p>Test passes if there is a filled green square and <strong>no red</strong>.</p>
+<div style="position:absolute; margin-left:10px; margin-top:10px; width:10px; height:90px; background:green;"></div>
+<div style="position:absolute; margin-left:60px; width:10px; height:90px; background:green;"></div>
+<div style="columns:2; column-fill:auto; gap:0; width:100px; height:100px; background:red;">
+  <div style="width:32px; height:180px; direction:rtl; border:solid 10px green; border-right-width:8px;">
+    <div style="position:relative;">
+      <div style="position:absolute; width:22px; height:180px; background:green;"></div>
+    </div>
+  </div>
+</div>
diff --git a/tests/wpt/web-platform-tests/css/css-contain/content-visibility/content-visibility-auto-state-changed-first-observation.html b/tests/wpt/web-platform-tests/css/css-contain/content-visibility/content-visibility-auto-state-changed-first-observation.html
new file mode 100644
index 00000000000..1c518514881
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-contain/content-visibility/content-visibility-auto-state-changed-first-observation.html
@@ -0,0 +1,65 @@
+<!doctype HTML>
+<html>
+<meta charset="utf8">
+<title>Content Visibility: ContentVisibilityAutoStateChange event.</title>
+<link rel="author" title="Vladimir Levin" href="mailto:vmpstr@chromium.org">
+<link rel="help" href="https://drafts.csswg.org/css-contain/#content-visibility">
+<meta name="assert" content="ContentVisibilityAutoStateChange fires once when element is inserted">
+
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<style>
+.spacer {
+  height: 10000px;
+}
+</style>
+
+<div id=topdiv></div>
+<div class=spacer></div>
+<div id=bottomdiv></div>
+
+<script>
+promise_test(t => new Promise(async (resolve, reject) => {
+  await new Promise((waited, _) => {
+    requestAnimationFrame(() => requestAnimationFrame(waited));
+  });
+
+  let observed = false;
+  let div = document.createElement("div");
+  div.addEventListener("contentvisibilityautostatechange", (e) => {
+    if (observed)
+      reject("already observed");
+    if (e.skipped)
+      reject("unexpected skipped");
+    observed = true;
+    // Wait a couple of frames to ensure no other signal comes in
+    requestAnimationFrame(() => requestAnimationFrame(resolve));
+  });
+
+  div.style.contentVisibility = "auto";
+  topdiv.appendChild(div);
+}), "ContentVisibilityAutoStateChange fires once when added (not skipped)");
+
+promise_test(t => new Promise(async (resolve, reject) => {
+  await new Promise((waited, _) => {
+    requestAnimationFrame(() => requestAnimationFrame(waited));
+  });
+
+  let observed = false;
+  let div = document.createElement("div");
+  div.addEventListener("contentvisibilityautostatechange", (e) => {
+    if (observed)
+      reject("already observed");
+    if (!e.skipped)
+      reject("unexpected not skipped");
+    observed = true;
+    // Wait a couple of frames to ensure no other signal comes in
+    requestAnimationFrame(() => requestAnimationFrame(resolve));
+  });
+
+  div.style.contentVisibility = "auto";
+  bottomdiv.appendChild(div);
+}), "ContentVisibilityAutoStateChange fires once when added (skipped)");
+</script>
+
diff --git a/tests/wpt/web-platform-tests/css/css-flexbox/inline-flexbox-vertical-rl-image-flexitem-crash-print.html b/tests/wpt/web-platform-tests/css/css-flexbox/inline-flexbox-vertical-rl-image-flexitem-crash-print.html
new file mode 100644
index 00000000000..0de07b18705
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-flexbox/inline-flexbox-vertical-rl-image-flexitem-crash-print.html
@@ -0,0 +1,22 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<link rel="author" title="Ting-Yu Lin" href="mailto:tlin@mozilla.com">
+<link rel="author" title="Mozilla" href="https://www.mozilla.org/">
+<link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1805522">
+<!-- This is a printing crashtest, but wpt doesn't support it.
+     We work around it by ensuring the test renders something non-blank. -->
+<link rel="mismatch" href="/common/blank.html">
+<style>
+#a {
+  height: 0.473em;
+  writing-mode: vertical-rl;
+  display: -webkit-inline-box;
+}
+#b {
+  overflow-x: scroll;
+  height: fit-content;
+  content: url(data:image/gif;base64,R0lGODlhEAAQAMQAAORHHOVSKudfOulrSOp3WOyDZu6QdvCchPGolfO0o/XBs/fNwfjZ0frl3/zy7////wAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACH5BAkAABAALAAAAAAQABAAAAVVICSOZGlCQAosJ6mu7fiyZeKqNKToQGDsM8hBADgUXoGAiqhSvp5QAnQKGIgUhwFUYLCVDFCrKUE1lBavAViFIDlTImbKC5Gm2hB0SlBCBMQiB0UjIQA7)
+}
+</style>
+<dl id="a">
+<dd id="b">
diff --git a/tests/wpt/web-platform-tests/css/css-fonts/font-variant-alternates-19-ref.html b/tests/wpt/web-platform-tests/css/css-fonts/font-variant-alternates-19-ref.html
new file mode 100644
index 00000000000..22c178c64f2
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-fonts/font-variant-alternates-19-ref.html
@@ -0,0 +1,25 @@
+<!DOCTYPE html>
+<html lang="en">
+<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
+<title>CSS Test:  font-variant-alternates: multiple @font-feature-values rules</title>
+<link rel="author" title="Dominik Röttsches" href="drott@chromium.org">
+<style>
+  @font-face {
+    font-family: fwf;
+    src: url(support/fonts/FontWithFancyFeatures.otf);
+  }
+  .test {
+	  font-family: fwf;
+	  font-size: 2em;
+	  line-height: 1.1;
+  }
+</style>
+<body>
+
+<p>Test passes if the three lines below are identical, with 4 crosses (✗), then
+three check marks (✓), then 11 crosses (✗), then 1 checkmark (✓).</p>
+<section class="test">
+  <p class="ref">BBBBAAABBBBBBBBBBBAB</p>
+  <p class="ref">BBBBAAABBBBBBBBBBBAB</p>
+  <p class="ref">BBBBAAABBBBBBBBBBBAB</p>
+</section>
diff --git a/tests/wpt/web-platform-tests/css/css-fonts/font-variant-alternates-19.html b/tests/wpt/web-platform-tests/css/css-fonts/font-variant-alternates-19.html
new file mode 100644
index 00000000000..6e9caf2e47c
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-fonts/font-variant-alternates-19.html
@@ -0,0 +1,57 @@
+<!DOCTYPE html>
+<html lang="en">
+<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
+<title>CSS Test:  font-variant-alternates: multiple @font-feature-values rules</title>
+<link rel="author" title="Dominik Röttsches" href="drott@chromium.org">
+<link rel="match" href="font-variant-alternates-19-ref.html">
+<link rel="help" href="https://www.w3.org/TR/css-fonts-4/#font-variant-alternates-prop">
+<link rel="help" href="https://www.w3.org/TR/css-fonts-4/#font-feature-settings-prop">
+<link rel="help" href="https://drafts.csswg.org/css-fonts/#font-feature-values">
+<meta name="assert" content="If multiple @font-feature-values rules are defined for a given family, the
+resulting values definitions are the union of the definitions contained within these rules.">
+<style>
+  @font-face {
+    font-family: fwf;
+    src: url(support/fonts/FontWithFancyFeatures.otf);
+  }
+  @font-feature-values fwf {
+    @styleset {
+      foo: 4;
+      bar: 2;
+    }
+  }
+  @font-feature-values fwf {
+    @styleset {
+      baz: 3;
+    }
+  }
+  @font-feature-values fwf {
+    @styleset {
+      foo: 1; /* Overrides foo from first rule. */
+    }
+    @ornaments {
+      baz: 3;
+    }
+  }
+  .test {
+	  font-family: fwf;
+	  font-size: 2em;
+	  line-height: 1.1;
+  }
+  .high {
+	 font-variant-alternates: styleset(foo,bar,baz) ornaments(baz);
+  }
+  .low {
+   font-feature-settings: "hist" off, "salt" 00, "ss01" on, "ss02" on, "ss03" on,
+    "cv01" off, "cv02" off, "cv03" off,  "swsh" 00, "cswh" 00, "ornm" 03, "nalt" 00;
+  }
+</style>
+<body>
+
+<p>Test passes if the three lines below are identical, with 4 crosses (✗), then
+three check marks (✓), then 11 crosses (✗), then 1 checkmark (✓).</p>
+<section class="test">
+  <p class="high">Xnophijklmqrstuvwxyz</p>
+  <p class="low">Xnophijklmqrstuvwxyz</p>
+  <p class="ref">BBBBAAABBBBBBBBBBBAB</p>
+</section>
diff --git a/tests/wpt/web-platform-tests/css/css-fonts/parsing/font-variant-alternates-invalid.html b/tests/wpt/web-platform-tests/css/css-fonts/parsing/font-variant-alternates-invalid.html
index baf35acb8a1..8cd17d0849f 100644
--- a/tests/wpt/web-platform-tests/css/css-fonts/parsing/font-variant-alternates-invalid.html
+++ b/tests/wpt/web-platform-tests/css/css-fonts/parsing/font-variant-alternates-invalid.html
@@ -34,6 +34,7 @@
         "font-variant-alternates",
         "historical-forms(argument)"
       );
+      test_invalid_value("font-variant-alternates", "annotation()");
       test_invalid_value("font-variant-alternates", "annotation");
       test_invalid_value("font-variant-alternates", "swash");
       test_invalid_value("font-variant-alternates", "ornaments stylistic");
diff --git a/tests/wpt/web-platform-tests/css/css-images/gradient/css-color-4-colors-default-to-oklab-gradient.html b/tests/wpt/web-platform-tests/css/css-images/gradient/css-color-4-colors-default-to-oklab-gradient.html
index 5be18ac30ff..63fdd6f4a44 100644
--- a/tests/wpt/web-platform-tests/css/css-images/gradient/css-color-4-colors-default-to-oklab-gradient.html
+++ b/tests/wpt/web-platform-tests/css/css-images/gradient/css-color-4-colors-default-to-oklab-gradient.html
@@ -11,7 +11,7 @@
    .test {
        width: 480px;
        height: 50px;
-       background: linear-gradient(to right, rgb(255, 0, 0), color(srgb 0 255 0));
+       background: linear-gradient(to right, rgb(255, 0, 0), color(srgb 0 1 0));
    }
  </style>
  </head>
diff --git a/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-content-rendering-ref.html b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-content-rendering-ref.html
deleted file mode 100644
index 29316bc1a6b..00000000000
--- a/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-content-rendering-ref.html
+++ /dev/null
@@ -1,11 +0,0 @@
-<!doctype html>
-<title>CSS Test Reference</title>
-<style>
-  .test {
-    display: inline-block;
-    width: 100px;
-    height: 100px;
-    background: red;
-  }
-</style>
-<div class="test" style="content: url('/images/green.png')" ></div>
diff --git a/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-content-rendering.html b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-content-rendering.html
index 9110837abd7..f0622a89506 100644
--- a/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-content-rendering.html
+++ b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-content-rendering.html
@@ -1,16 +1,15 @@
-<!doctype html>
+<!DOCTYPE html>
 <title>Image set is supported in the content property</title>
 <link rel="author" title="Emilio Cobos Álvarez" href="mailto:emilio@crisal.io">
 <link rel="author" title="Noam Rosenthal" href="mailto:noam@webkit.org">
+<link rel="author" title="Traian Captan" href="mailto:tcaptan@chromium.org">
 <link rel="help" href="https://drafts.csswg.org/css-images-4/#image-set-notation">
 <link rel="help" href="https://drafts.csswg.org/css-content/#content-property">
-<link rel="match"  href="image-set-content-rendering-ref.html">
+<link rel="match"  href="reference/image-set-content-rendering-ref.html">
+<meta name="assert" content="image-set content rendering">
+<script src="resources/image-set-rendering-helper.js"></script>
 <style>
-  .test {
-    display: inline-block;
-    width: 100px;
-    height: 100px;
-    background: red;
+  #test {
+    content: image-set(url("/images/green.png") 1x);
   }
 </style>
-<div class="test" style="content: image-set(url() 2x, url('/images/green.png') 100dpi)" ></div>
diff --git a/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-dpi-rendering-2.html b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-dpi-rendering-2.html
new file mode 100644
index 00000000000..d7bd02e7677
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-dpi-rendering-2.html
@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+<title>Image set dpi rendering</title>
+<link rel="author" title="Noam Rosenthal" href="mailto:noam@webkit.org">
+<link rel="author" title="Traian Captan" href="mailto:tcaptan@chromium.org">
+<link rel="help" href="https://drafts.csswg.org/css-images-4/#image-set-notation">
+<link rel="match" href="reference/image-set-rendering-ref.html">
+<meta name="assert" content="image-set dpi rendering">
+<script src="resources/image-set-rendering-helper.js"></script>
+<style>
+  #test {
+    background-image: image-set(
+      url("/images/green.png") 96dpi,
+      url("/images/red.png") 100dpi
+    );
+  }
+</style>
diff --git a/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-dpi-rendering.html b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-dpi-rendering.html
new file mode 100644
index 00000000000..be18e85ffb0
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-dpi-rendering.html
@@ -0,0 +1,13 @@
+<!DOCTYPE html>
+<title>Image set dpi rendering</title>
+<link rel="author" title="Noam Rosenthal" href="mailto:noam@webkit.org">
+<link rel="author" title="Traian Captan" href="mailto:tcaptan@chromium.org">
+<link rel="help" href="https://drafts.csswg.org/css-images-4/#image-set-notation">
+<link rel="match" href="reference/image-set-rendering-ref.html">
+<meta name="assert" content="image-set dpi rendering">
+<script src="resources/image-set-rendering-helper.js"></script>
+<style>
+  #test {
+    background-image: image-set(url("/images/green.png") 96dpi);
+  }
+</style>
diff --git a/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-dppx-rendering.html b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-dppx-rendering.html
new file mode 100644
index 00000000000..1fc2f8c85d9
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-dppx-rendering.html
@@ -0,0 +1,13 @@
+<!DOCTYPE html>
+<title>Image set dppx rendering</title>
+<link rel="author" title="Noam Rosenthal" href="mailto:noam@webkit.org">
+<link rel="author" title="Traian Captan" href="mailto:tcaptan@chromium.org">
+<link rel="help" href="https://drafts.csswg.org/css-images-4/#image-set-notation">
+<link rel="match" href="reference/image-set-rendering-ref.html">
+<meta name="assert" content="image-set dppx rendering">
+<script src="resources/image-set-rendering-helper.js"></script>
+<style>
+  #test {
+    background-image: image-set(url("/images/green.png") 1dppx);
+  }
+</style>
diff --git a/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-empty-url-rendering.html b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-empty-url-rendering.html
new file mode 100644
index 00000000000..0286d7372f0
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-empty-url-rendering.html
@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+<title>Image set empty url rendering</title>
+<link rel="author" title="Noam Rosenthal" href="mailto:noam@webkit.org">
+<link rel="author" title="Traian Captan" href="mailto:tcaptan@chromium.org">
+<link rel="help" href="https://drafts.csswg.org/css-images-4/#image-set-notation">
+<link rel="match" href="reference/image-set-rendering-ref.html">
+<meta name="assert" content="image-set rendering when 2x url is empty">
+<script src="resources/image-set-rendering-helper.js"></script>
+<style>
+  #test {
+    background-image: image-set(
+      url("/images/green.png") 1x,
+      url("") 2x
+    );
+  }
+</style>
diff --git a/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-first-match-rendering.html b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-first-match-rendering.html
new file mode 100644
index 00000000000..4d5b9d7d9ce
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-first-match-rendering.html
@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+<title>Image set type first match rendering</title>
+<link rel="author" title="Noam Rosenthal" href="mailto:noam@webkit.org">
+<link rel="author" title="Traian Captan" href="mailto:tcaptan@chromium.org">
+<link rel="help" href="https://drafts.csswg.org/css-images-4/#image-set-notation">
+<link rel="match" href="reference/image-set-rendering-ref.html">
+<meta name="assert" content="image-set rendering picks first valid match">
+<script src="resources/image-set-rendering-helper.js"></script>
+<style>
+  #test {
+    background-image: image-set(
+      url("/images/green.png") 1x,
+      url("/images/red.png") 1x
+    );
+  }
+</style>
diff --git a/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-invalid-resolution-rendering-2.html b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-invalid-resolution-rendering-2.html
new file mode 100644
index 00000000000..88917e1e3f7
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-invalid-resolution-rendering-2.html
@@ -0,0 +1,17 @@
+<!DOCTYPE html>
+<title>Image set invalid resolution rendering</title>
+<link rel="author" title="Noam Rosenthal" href="mailto:noam@webkit.org">
+<link rel="author" title="Traian Captan" href="mailto:tcaptan@chromium.org">
+<link rel="help" href="https://drafts.csswg.org/css-images-4/#image-set-notation">
+<link rel="match" href="reference/image-set-rendering-ref.html">
+<meta name="assert" content="image-set rendering when resolution is invalid">
+<script src="resources/image-set-rendering-helper.js"></script>
+<style>
+  #test {
+    background-image: url("/images/green.png");
+    background-image: image-set(
+      url("/images/red.png") 0x,
+      url("/images/red.png") 2x
+    );
+  }
+</style>
diff --git a/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-invalid-resolution-rendering.html b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-invalid-resolution-rendering.html
new file mode 100644
index 00000000000..0cdcf6018e6
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-invalid-resolution-rendering.html
@@ -0,0 +1,14 @@
+<!DOCTYPE html>
+<title>Image set invalid resolution rendering</title>
+<link rel="author" title="Noam Rosenthal" href="mailto:noam@webkit.org">
+<link rel="author" title="Traian Captan" href="mailto:tcaptan@chromium.org">
+<link rel="help" href="https://drafts.csswg.org/css-images-4/#image-set-notation">
+<link rel="match" href="reference/image-set-rendering-ref.html">
+<meta name="assert" content="image-set rendering when resolution is invalid">
+<script src="resources/image-set-rendering-helper.js"></script>
+<style>
+  #test {
+    background-image: url("/images/green.png");
+    background-image: image-set(url("/images/red.png") 0x);
+  }
+</style>
diff --git a/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-linear-gradient-rendering.html b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-linear-gradient-rendering.html
new file mode 100644
index 00000000000..62f41a743f2
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-linear-gradient-rendering.html
@@ -0,0 +1,13 @@
+<!DOCTYPE html>
+<title>Image set linear-gradient rendering</title>
+<link rel="author" title="Noam Rosenthal" href="mailto:noam@webkit.org">
+<link rel="author" title="Traian Captan" href="mailto:tcaptan@chromium.org">
+<link rel="help" href="https://drafts.csswg.org/css-images-4/#image-set-notation">
+<link rel="match" href="reference/image-set-linear-gradient-rendering-ref.html">
+<meta name="assert" content="image-set linear-gradient rendering">
+<script src="resources/image-set-rendering-helper.js"></script>
+<style>
+  #test {
+    background-image: image-set(linear-gradient(green, lightgreen) 1x);
+  }
+</style>
diff --git a/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-no-res-rendering.html b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-no-res-rendering.html
new file mode 100644
index 00000000000..927d4c67f1d
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-no-res-rendering.html
@@ -0,0 +1,13 @@
+<!DOCTYPE html>
+<title>Image set no resolution rendering</title>
+<link rel="author" title="Noam Rosenthal" href="mailto:noam@webkit.org">
+<link rel="author" title="Traian Captan" href="mailto:tcaptan@chromium.org">
+<link rel="help" href="https://drafts.csswg.org/css-images-4/#image-set-notation">
+<link rel="match" href="reference/image-set-rendering-ref.html">
+<meta name="assert" content="image-set rendering with no resolution defined">
+<script src="resources/image-set-rendering-helper.js"></script>
+<style>
+  #test {
+    background-image: image-set(url("/images/green.png"));
+  }
+</style>
diff --git a/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-no-url-rendering.html b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-no-url-rendering.html
new file mode 100644
index 00000000000..7af722d7c06
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-no-url-rendering.html
@@ -0,0 +1,13 @@
+<!DOCTYPE html>
+<title>Image set no url rendering</title>
+<link rel="author" title="Noam Rosenthal" href="mailto:noam@webkit.org">
+<link rel="author" title="Traian Captan" href="mailto:tcaptan@chromium.org">
+<link rel="help" href="https://drafts.csswg.org/css-images-4/#image-set-notation">
+<link rel="match" href="reference/image-set-rendering-ref.html">
+<meta name="assert" content="image-set without url functional notation rendering">
+<script src="resources/image-set-rendering-helper.js"></script>
+<style>
+  #test {
+    background-image: image-set("/images/green.png" 1x);
+  }
+</style>
diff --git a/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-radial-gradient-rendering.html b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-radial-gradient-rendering.html
new file mode 100644
index 00000000000..7bf950a4037
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-radial-gradient-rendering.html
@@ -0,0 +1,13 @@
+<!DOCTYPE html>
+<title>Image set radial-gradient rendering</title>
+<link rel="author" title="Noam Rosenthal" href="mailto:noam@webkit.org">
+<link rel="author" title="Traian Captan" href="mailto:tcaptan@chromium.org">
+<link rel="help" href="https://drafts.csswg.org/css-images-4/#image-set-notation">
+<link rel="match" href="reference/image-set-radial-gradient-rendering-ref.html">
+<meta name="assert" content="image-set radial-gradient rendering">
+<script src="resources/image-set-rendering-helper.js"></script>
+<style>
+  #test {
+    background-image: image-set(radial-gradient(green, lightgreen) 1x);
+  }
+</style>
diff --git a/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-rendering-2.html b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-rendering-2.html
new file mode 100644
index 00000000000..a6724553d62
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-rendering-2.html
@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+<title>Image set rendering</title>
+<link rel="author" title="Noam Rosenthal" href="mailto:noam@webkit.org">
+<link rel="author" title="Traian Captan" href="mailto:tcaptan@chromium.org">
+<link rel="help" href="https://drafts.csswg.org/css-images-4/#image-set-notation">
+<link rel="match" href="reference/image-set-rendering-ref.html">
+<meta name="assert" content="image-set rendering">
+<script src="resources/image-set-rendering-helper.js"></script>
+<style>
+  #test {
+    background-image: image-set(
+      url("/images/green.png") 1x,
+      url("/images/red.png") 2x
+    );
+  }
+</style>
diff --git a/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-rendering-ref.html b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-rendering-ref.html
deleted file mode 100644
index 081766ce7db..00000000000
--- a/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-rendering-ref.html
+++ /dev/null
@@ -1,44 +0,0 @@
-<!DOCTYPE html>
-<html>
-    <head>
-        <title>Image set rendering</title>
-        <link rel="author" title="Noam Rosenthal" href="mailto:noam@webkit.org">
-        <link rel="help" href="https://drafts.csswg.org/css-images-4/#image-set-notation">
-        <meta name="assert" content="image-set rendering">
-        <style>
-            .test {
-                display: inline-block;
-                width: 100px;
-                height: 100px;
-            }
-
-            main {
-                width: 500px;
-            }
-        </style>
-    </head>
-    <body>
-        <p>All images below should be lime or a lime-green gradient when devicePixelRatio is 1 - no red!.</p>
-        <main>
-            <div class="test" style="background-image: url(/images/green.png)"></div>
-            <div class="test" style="background-image: linear-gradient(green, lightgreen)"></div>
-            <div class="test" style="background-image: url('/images/green.png')" ></div>
-            <div class="test" style="background-image: radial-gradient(green, lightgreen)" ></div>
-            <div class="test" style="background-image: linear-gradient(green, lightgreen)" ></div>
-            <div class="test" style="background-image: url('/images/green.png')" ></div>
-            <div class="test" style="background-image: url('/images/green.png')" ></div>
-            <div class="test" style="background-image: url('/images/green.png')" ></div>
-            <div class="test" style="background-image: url('/images/green.png')"></div>
-            <div class="test" style="background-color: lime"></div>
-            <div class="test" style="background-color: lime"></div>
-            <div class="test" style="background-color: lime"></div>
-            <div class="test" style="background-image: url(/images/green.png)"></div>
-            <div class="test" style="background-image: url(/images/green.png)"></div>
-            <div class="test" style="background-image: url(/images/green.png)"></div>
-            <div class="test" style="background-image: url(/images/red.png)"></div>
-            <div class="test" style="background-image: url(/images/green.png)"></div>
-            <div class="test" style="background-image: url(/images/red.png)"></div>
-            <div class="test" style="background-image: url(/images/green.png)"></div>
-        </main>
-    </body>
-</html>
diff --git a/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-rendering.html b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-rendering.html
index eb3ece9654e..ce4a900403d 100644
--- a/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-rendering.html
+++ b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-rendering.html
@@ -1,46 +1,13 @@
 <!DOCTYPE html>
-<html>
-    <head>
-        <title>Image set rendering</title>
-        <link rel="author" title="Noam Rosenthal" href="mailto:noam@webkit.org">
-        <link rel="help" href="https://drafts.csswg.org/css-images-4/#image-set-notation">
-        <meta name="assert" content="image-set rendering">
-        <link rel="match"  href="image-set-rendering-ref.html">
-        <style>
-            .test {
-                display: inline-block;
-                width: 100px;
-                height: 100px;
-                background: red;
-            }
-
-            main {
-                width: 500px;
-            }
-        </style>
-    </head>
-    <body>
-        <p>All images below should be lime or a lime-green gradient when devicePixelRatio is 1 - no red!.</p>
-        <main>
-            <div class="test" style="background-image: image-set('/images/green.png' 1x)"></div>
-            <div class="test" style="background-image: image-set('/images/red.png' 20dpi, linear-gradient(green, lightgreen) 2x)"></div>
-            <div class="test" style="background-image: image-set(url('/images/green.png') 1x, url('/images/red.png') 2x)" ></div>
-            <div class="test" style="background-image: image-set(radial-gradient(green, lightgreen) 1x, linear-gradient(yellow, red) 2x)" ></div>
-            <div class="test" style="background-image: image-set(linear-gradient(green, lightgreen) 96dpi, '/images/red.png' 100dpi)" ></div>
-            <div class="test" style="background-image: image-set(radial-gradient(red, yellow) 1.3x, url('/images/green.png') 100dpi, linear-gradient(red, yellow) 2.5x)" ></div>
-            <div class="test" style="background-image: image-set('/images/red.png' 2x, url('/images/green.png') 1x, url('/images/yellow.png') 300dpi)" ></div>
-            <div class="test" style="background-color: red; background-image: image-set('' 2x, url('/images/green.png') 1x)" ></div>
-            <div class="test" style="background-image: image-set('/images/green.png' 1x)"></div>
-            <div class="test" style="background-color: red; background-image: image-set('/images/green.png')" ></div>
-            <div class="test" style="background-color: lime; background-image: image-set('/images/red.png' 0x)" ></div>
-            <div class="test" style="background-color: lime; background-image: image-set('/images/red.png' 0x, url('/images/red.png') 2x)" ></div>
-            <div class="test" style="background-image: image-set('/images/green.png' type('image/png') 1x)"></div>
-            <div class="test" style="background-image: image-set('/images/green.png' 1x type('image/png'))"></div>
-            <div class="test" style="background-image: image-set('/images/green.png' type('image/png'))"></div>
-            <div class="test" style="background-image: image-set('/images/red.png' type('image/png'), '/images/green.png' type('image/png'))"></div>
-            <div class="test" style="background-image: image-set('/images/red.png' type('image/unsupported'), '/images/green.png' type('image/png'))"></div>
-            <div class="test" style="background-image: image-set('/images/red.png' type('image/unsupported'), '/images/green.png' type('image/unsupported'))"></div>
-            <div class="test" style="background-image: image-set('/images/red.png' 2x type('image/png'), '/images/green.png' 1x type('image/png'))"></div>
-        </main>
-    </body>
-</html>
+<title>Image set rendering</title>
+<link rel="author" title="Noam Rosenthal" href="mailto:noam@webkit.org">
+<link rel="author" title="Traian Captan" href="mailto:tcaptan@chromium.org">
+<link rel="help" href="https://drafts.csswg.org/css-images-4/#image-set-notation">
+<link rel="match" href="reference/image-set-rendering-ref.html">
+<meta name="assert" content="image-set rendering">
+<script src="resources/image-set-rendering-helper.js"></script>
+<style>
+  #test {
+    background-image: image-set(url("/images/green.png") 1x);
+  }
+</style>
diff --git a/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-type-first-match-rendering.html b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-type-first-match-rendering.html
new file mode 100644
index 00000000000..1283d22d1ff
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-type-first-match-rendering.html
@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+<title>Image set type first match rendering</title>
+<link rel="author" title="Noam Rosenthal" href="mailto:noam@webkit.org">
+<link rel="author" title="Traian Captan" href="mailto:tcaptan@chromium.org">
+<link rel="help" href="https://drafts.csswg.org/css-images-4/#image-set-notation">
+<link rel="match" href="reference/image-set-rendering-ref.html">
+<meta name="assert" content="image-set rendering with type picks first valid match">
+<script src="resources/image-set-rendering-helper.js"></script>
+<style>
+  #test {
+    background-image: image-set(
+      url("/images/green.png") 1x type('image/png'),
+      url("/images/red.png") 1x type('image/png')
+    );
+  }
+</style>
diff --git a/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-type-rendering-2.html b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-type-rendering-2.html
new file mode 100644
index 00000000000..897118acd60
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-type-rendering-2.html
@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+<title>Image set type rendering</title>
+<link rel="author" title="Noam Rosenthal" href="mailto:noam@webkit.org">
+<link rel="author" title="Traian Captan" href="mailto:tcaptan@chromium.org">
+<link rel="help" href="https://drafts.csswg.org/css-images-4/#image-set-notation">
+<link rel="match" href="reference/image-set-rendering-ref.html">
+<meta name="assert" content="image-set rendering for images with same type but different resolutions">
+<script src="resources/image-set-rendering-helper.js"></script>
+<style>
+  #test {
+    background-image: image-set(
+      url("/images/green.png") type('image/png') 1x,
+      url("/images/red.png") type('image/png') 2x
+    );
+  }
+</style>
diff --git a/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-type-rendering-3.html b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-type-rendering-3.html
new file mode 100644
index 00000000000..51dbe2c9221
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-type-rendering-3.html
@@ -0,0 +1,13 @@
+<!DOCTYPE html>
+<title>Image set type rendering</title>
+<link rel="author" title="Noam Rosenthal" href="mailto:noam@webkit.org">
+<link rel="author" title="Traian Captan" href="mailto:tcaptan@chromium.org">
+<link rel="help" href="https://drafts.csswg.org/css-images-4/#image-set-notation">
+<link rel="match" href="reference/image-set-rendering-ref.html">
+<meta name="assert" content="image-set rendering with type before resolution">
+<script src="resources/image-set-rendering-helper.js"></script>
+<style>
+  #test {
+    background-image: image-set(url("/images/green.png") type('image/png') 1x);
+  }
+</style>
diff --git a/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-type-rendering.html b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-type-rendering.html
new file mode 100644
index 00000000000..16055dbccf7
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-type-rendering.html
@@ -0,0 +1,13 @@
+<!DOCTYPE html>
+<title>Image set type rendering</title>
+<link rel="author" title="Noam Rosenthal" href="mailto:noam@webkit.org">
+<link rel="author" title="Traian Captan" href="mailto:tcaptan@chromium.org">
+<link rel="help" href="https://drafts.csswg.org/css-images-4/#image-set-notation">
+<link rel="match" href="reference/image-set-rendering-ref.html">
+<meta name="assert" content="image-set rendering with type">
+<script src="resources/image-set-rendering-helper.js"></script>
+<style>
+  #test {
+    background-image: image-set(url("/images/green.png") 1x type('image/png'));
+  }
+</style>
diff --git a/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-type-skip-unsupported-rendering.html b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-type-skip-unsupported-rendering.html
new file mode 100644
index 00000000000..e555633cdda
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-type-skip-unsupported-rendering.html
@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+<title>Image set type skip unsupported rendering</title>
+<link rel="author" title="Noam Rosenthal" href="mailto:noam@webkit.org">
+<link rel="author" title="Traian Captan" href="mailto:tcaptan@chromium.org">
+<link rel="help" href="https://drafts.csswg.org/css-images-4/#image-set-notation">
+<link rel="match" href="reference/image-set-rendering-ref.html">
+<meta name="assert" content="image-set rendering with type skips unsupported type">
+<script src="resources/image-set-rendering-helper.js"></script>
+<style>
+  #test {
+    background-image: image-set(
+      url("/images/red.png") 1x type('image/unsupported'),
+      url("/images/green.png") 1x type('image/png')
+    );
+  }
+</style>
diff --git a/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-type-unsupported-rendering-2.html b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-type-unsupported-rendering-2.html
new file mode 100644
index 00000000000..3f9fcd27d82
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-type-unsupported-rendering-2.html
@@ -0,0 +1,27 @@
+<!DOCTYPE html>
+<title>Image set type rendering</title>
+<link rel="author" title="Noam Rosenthal" href="mailto:noam@webkit.org">
+<link rel="author" title="Traian Captan" href="mailto:tcaptan@chromium.org">
+<link rel="help" href="https://drafts.csswg.org/css-images-4/#image-set-notation">
+<link rel="match" href="reference/image-set-rendering-ref.html">
+<meta name="assert" content="image-set rendering with all unsupported types">
+<!--
+Spec definition:
+"An image-set() function contains a list of one or more <image-set-option>s,
+  and must select only one of them to determine what image it will represent:
+  First, remove any <image-set-option>s from the list that specify
+  an unknown or unsupported MIME type in their type() value."
+
+If all the values in the image set are of an unsupported type,
+the set should be empty.
+-->
+<script src="resources/image-set-rendering-helper.js"></script>
+<style>
+  #test {
+    background-image: url("/images/green.png");
+    background-image: image-set(
+      url("/images/red.png") 1x type('image/unsupported'),
+      url("/images/red.png") 1x type('image/unsupported')
+    );
+  }
+</style>
diff --git a/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-type-unsupported-rendering.html b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-type-unsupported-rendering.html
new file mode 100644
index 00000000000..6e9e56a4eb0
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-type-unsupported-rendering.html
@@ -0,0 +1,24 @@
+<!DOCTYPE html>
+<title>Image set type rendering</title>
+<link rel="author" title="Noam Rosenthal" href="mailto:noam@webkit.org">
+<link rel="author" title="Traian Captan" href="mailto:tcaptan@chromium.org">
+<link rel="help" href="https://drafts.csswg.org/css-images-4/#image-set-notation">
+<link rel="match" href="reference/image-set-rendering-ref.html">
+<meta name="assert" content="image-set rendering with unsupported type">
+<!--
+Spec definition:
+"An image-set() function contains a list of one or more <image-set-option>s,
+  and must select only one of them to determine what image it will represent:
+  First, remove any <image-set-option>s from the list that specify
+  an unknown or unsupported MIME type in their type() value."
+
+If all the values in the image set are of an unsupported type,
+the set should be empty.
+-->
+<script src="resources/image-set-rendering-helper.js"></script>
+<style>
+  #test {
+    background-image: url("/images/green.png");
+    background-image: image-set(url("/images/red.png") 1x type('image/unsupported'));
+  }
+</style>
diff --git a/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-unordered-res-rendering.html b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-unordered-res-rendering.html
new file mode 100644
index 00000000000..c1063b74df6
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-images/image-set/image-set-unordered-res-rendering.html
@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+<title>Image set type unordered resolutions rendering</title>
+<link rel="author" title="Noam Rosenthal" href="mailto:noam@webkit.org">
+<link rel="author" title="Traian Captan" href="mailto:tcaptan@chromium.org">
+<link rel="help" href="https://drafts.csswg.org/css-images-4/#image-set-notation">
+<link rel="match" href="reference/image-set-rendering-ref.html">
+<meta name="assert" content="image-set rendering when resolutions are unordered">
+<script src="resources/image-set-rendering-helper.js"></script>
+<style>
+  #test {
+    background-image: image-set(
+      url("/images/red.png") 2x,
+      url("/images/green.png") 1x
+    );
+  }
+</style>
diff --git a/tests/wpt/web-platform-tests/css/css-images/image-set/reference/image-set-content-rendering-ref.html b/tests/wpt/web-platform-tests/css/css-images/image-set/reference/image-set-content-rendering-ref.html
new file mode 100644
index 00000000000..c1ef6d4531c
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-images/image-set/reference/image-set-content-rendering-ref.html
@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<title>Image set is supported in the content property</title>
+<link rel="author" title="Emilio Cobos Álvarez" href="mailto:emilio@crisal.io">
+<link rel="author" title="Noam Rosenthal" href="mailto:noam@webkit.org">
+<link rel="author" title="Traian Captan" href="mailto:tcaptan@chromium.org">
+<style>
+  #test {
+    content: url("/images/green.png");
+  }
+</style>
+<script src="../resources/image-set-rendering-helper.js"></script>
diff --git a/tests/wpt/web-platform-tests/css/css-images/image-set/reference/image-set-linear-gradient-rendering-ref.html b/tests/wpt/web-platform-tests/css/css-images/image-set/reference/image-set-linear-gradient-rendering-ref.html
new file mode 100644
index 00000000000..272bab9c582
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-images/image-set/reference/image-set-linear-gradient-rendering-ref.html
@@ -0,0 +1,10 @@
+<!DOCTYPE html>
+<title>Image set linear-gradient rendering</title>
+<link rel="author" title="Noam Rosenthal" href="mailto:noam@webkit.org">
+<link rel="author" title="Traian Captan" href="mailto:tcaptan@chromium.org">
+<style>
+  #test {
+    background-image: linear-gradient(green, lightgreen);
+  }
+</style>
+<script src="../resources/image-set-rendering-helper.js"></script>
diff --git a/tests/wpt/web-platform-tests/css/css-images/image-set/reference/image-set-radial-gradient-rendering-ref.html b/tests/wpt/web-platform-tests/css/css-images/image-set/reference/image-set-radial-gradient-rendering-ref.html
new file mode 100644
index 00000000000..f5545af5e6b
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-images/image-set/reference/image-set-radial-gradient-rendering-ref.html
@@ -0,0 +1,10 @@
+<!DOCTYPE html>
+<title>Image set radial-gradient rendering</title>
+<link rel="author" title="Noam Rosenthal" href="mailto:noam@webkit.org">
+<link rel="author" title="Traian Captan" href="mailto:tcaptan@chromium.org">
+<style>
+  #test {
+    background-image: radial-gradient(green, lightgreen);
+  }
+</style>
+<script src="../resources/image-set-rendering-helper.js"></script>
diff --git a/tests/wpt/web-platform-tests/css/css-images/image-set/reference/image-set-rendering-ref.html b/tests/wpt/web-platform-tests/css/css-images/image-set/reference/image-set-rendering-ref.html
new file mode 100644
index 00000000000..2ca6b3352d1
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-images/image-set/reference/image-set-rendering-ref.html
@@ -0,0 +1,10 @@
+<!DOCTYPE html>
+<title>Image set rendering</title>
+<link rel="author" title="Noam Rosenthal" href="mailto:noam@webkit.org">
+<link rel="author" title="Traian Captan" href="mailto:tcaptan@chromium.org">
+<style>
+  #test {
+    background-image: url("/images/green.png");
+  }
+</style>
+<script src="../resources/image-set-rendering-helper.js"></script>
diff --git a/tests/wpt/web-platform-tests/css/css-images/image-set/resources/image-set-rendering-helper.js b/tests/wpt/web-platform-tests/css/css-images/image-set/resources/image-set-rendering-helper.js
new file mode 100644
index 00000000000..7dbd50af882
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-images/image-set/resources/image-set-rendering-helper.js
@@ -0,0 +1,27 @@
+function setupTest() {
+  createPassingNotice();
+  createTestDiv();
+}
+
+function createPassingNotice() {
+  const notice = document.createElement('p');
+
+  notice.textContent =
+      'Test passes if the image below is green when devicePixelRatio is 1, not red.';
+
+  document.body.appendChild(notice);
+}
+
+function createTestDiv() {
+  const testDiv = document.createElement('div');
+
+  testDiv.id = 'test';
+
+  testDiv.style.width = '100px';
+  testDiv.style.height = '100px';
+  testDiv.style.backgroundColor = 'red';
+
+  document.body.appendChild(testDiv);
+}
+
+window.onload = setupTest;
diff --git a/tests/wpt/web-platform-tests/css/css-images/object-fit-contain-png-001c.html b/tests/wpt/web-platform-tests/css/css-images/object-fit-contain-png-001c.html
index 4fb7f113897..0f8195157e3 100644
--- a/tests/wpt/web-platform-tests/css/css-images/object-fit-contain-png-001c.html
+++ b/tests/wpt/web-platform-tests/css/css-images/object-fit-contain-png-001c.html
@@ -12,6 +12,7 @@
     <link rel="help" href="http://www.w3.org/TR/css3-images/#the-object-fit">
     <link rel="help" href="http://www.w3.org/TR/css3-images/#the-object-position">
     <link rel="match" href="object-fit-contain-png-001-ref.html">
+    <meta name=fuzzy content="maxDifference=0-20;totalPixels=0-2000">
     <style type="text/css">
       canvas {
         border: 1px dashed gray;
diff --git a/tests/wpt/web-platform-tests/css/css-images/object-fit-contain-png-002c.html b/tests/wpt/web-platform-tests/css/css-images/object-fit-contain-png-002c.html
index 738c015a52e..14834316a32 100644
--- a/tests/wpt/web-platform-tests/css/css-images/object-fit-contain-png-002c.html
+++ b/tests/wpt/web-platform-tests/css/css-images/object-fit-contain-png-002c.html
@@ -12,6 +12,7 @@
     <link rel="help" href="http://www.w3.org/TR/css3-images/#the-object-fit">
     <link rel="help" href="http://www.w3.org/TR/css3-images/#the-object-position">
     <link rel="match" href="object-fit-contain-png-002-ref.html">
+    <meta name=fuzzy content="maxDifference=0-20;totalPixels=0-2000">
     <style type="text/css">
       canvas {
         border: 1px dashed gray;
diff --git a/tests/wpt/web-platform-tests/css/css-images/object-fit-fill-png-001c.html b/tests/wpt/web-platform-tests/css/css-images/object-fit-fill-png-001c.html
index 36031175e63..0e2a3883fe2 100644
--- a/tests/wpt/web-platform-tests/css/css-images/object-fit-fill-png-001c.html
+++ b/tests/wpt/web-platform-tests/css/css-images/object-fit-fill-png-001c.html
@@ -12,6 +12,7 @@
     <link rel="help" href="http://www.w3.org/TR/css3-images/#the-object-fit">
     <link rel="help" href="http://www.w3.org/TR/css3-images/#the-object-position">
     <link rel="match" href="object-fit-fill-png-001-ref.html">
+    <meta name=fuzzy content="maxDifference=0-20;totalPixels=0-3200">
     <style type="text/css">
       canvas {
         border: 1px dashed gray;
diff --git a/tests/wpt/web-platform-tests/css/css-images/object-fit-fill-png-002c.html b/tests/wpt/web-platform-tests/css/css-images/object-fit-fill-png-002c.html
index a332c37f4f0..43bcced9f26 100644
--- a/tests/wpt/web-platform-tests/css/css-images/object-fit-fill-png-002c.html
+++ b/tests/wpt/web-platform-tests/css/css-images/object-fit-fill-png-002c.html
@@ -12,6 +12,7 @@
     <link rel="help" href="http://www.w3.org/TR/css3-images/#the-object-fit">
     <link rel="help" href="http://www.w3.org/TR/css3-images/#the-object-position">
     <link rel="match" href="object-fit-fill-png-002-ref.html">
+    <meta name=fuzzy content="maxDifference=0-20;totalPixels=0-3200">
     <style type="text/css">
       canvas {
         border: 1px dashed gray;
diff --git a/tests/wpt/web-platform-tests/css/css-overflow/scrollable-overflow-zero-one-axis.html b/tests/wpt/web-platform-tests/css/css-overflow/scrollable-overflow-zero-one-axis.html
new file mode 100644
index 00000000000..1986a8d48b9
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-overflow/scrollable-overflow-zero-one-axis.html
@@ -0,0 +1,59 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Overflow: Scroll Length Calculated Correctly When One Axis Has Zero Length</title>
+<link rel="author" title="David Shin" href="mailto:dshin@mozilla.com">
+<link rel="author" title="Mozilla" href="http://www.mozilla.org/">
+<link rel="help" href="https://drafts.csswg.org/css-overflow-3/#scrollable">
+<link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1800907">
+<style>
+.scroll {
+  overflow: scroll;
+}
+
+.zero-h {
+  width: 100px;
+  height: 0px;
+}
+
+.zero-w {
+  width: 0;
+  height: 100px;
+}
+
+.flex-row {
+  display: flex;
+}
+
+.flex-col {
+  display: flex;
+  flex-direction: column;
+}
+
+.grid {
+  display: grid;
+}
+</style>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/check-layout-th.js"></script>
+<body onload="checkLayout('.scroll')">
+<div class="scroll zero-h" data-expected-scroll-height="100">
+  <div class="zero-w"></div>
+</div>
+<div class="scroll zero-w" data-expected-scroll-width="100">
+  <div class="zero-h"></div>
+</div>
+
+<div class="scroll zero-h flex-row" data-expected-scroll-height="100">
+  <div class="zero-w"></div>
+</div>
+<div class="scroll zero-w flex-col" data-expected-scroll-width="100">
+  <div class="zero-h"></div>
+</div>
+
+<div class="scroll zero-h grid" data-expected-scroll-height="100">
+  <div class="zero-w"></div>
+</div>
+<div class="scroll zero-w grid" data-expected-scroll-width="100">
+  <div class="zero-h"></div>
+</div>
diff --git a/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-angle.html b/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-angle.html
new file mode 100644
index 00000000000..0cb06aef0bd
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-angle.html
@@ -0,0 +1,57 @@
+<!DOCTYPE html>
+<link rel="help" href="https://drafts.css-houdini.org/css-properties-values-api-1">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../resources/utils.js"></script>
+<div id="target"></div>
+<script>
+
+animation_test({
+  syntax: "<angle>",
+  inherits: false,
+  initialValue: "0deg"
+}, {
+  keyframes: ["100deg", "200deg"],
+  expected: "150deg"
+}, 'Animating a custom property of type <angle>');
+
+animation_test({
+  syntax: "<angle>",
+  inherits: false,
+  initialValue: "100deg"
+}, {
+  keyframes: "200deg",
+  expected: "150deg"
+}, 'Animating a custom property of type <angle> with a single keyframe');
+
+animation_test({
+  syntax: "<angle>",
+  inherits: false,
+  initialValue: "100deg"
+}, {
+  composite: "add",
+  keyframes: ["200deg", "300deg"],
+  expected: "350deg"
+}, 'Animating a custom property of type <angle> with additivity');
+
+animation_test({
+  syntax: "<angle>",
+  inherits: false,
+  initialValue: "100deg"
+}, {
+  composite: "add",
+  keyframes: "300deg",
+  expected: "250deg"
+}, 'Animating a custom property of type <angle> with a single keyframe and additivity');
+
+animation_test({
+  syntax: "<angle>",
+  inherits: false,
+  initialValue: "100deg"
+}, {
+  iterationComposite: "accumulate",
+  keyframes: ["0deg", "100deg"],
+  expected: "250deg"
+}, 'Animating a custom property of type <angle> with iterationComposite');
+
+</script>
diff --git a/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-color.html b/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-color.html
new file mode 100644
index 00000000000..001fc407e7b
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-color.html
@@ -0,0 +1,57 @@
+<!DOCTYPE html>
+<link rel="help" href="https://drafts.css-houdini.org/css-properties-values-api-1">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../resources/utils.js"></script>
+<div id="target"></div>
+<script>
+
+animation_test({
+  syntax: "<color>",
+  inherits: false,
+  initialValue: "black"
+}, {
+  keyframes: ["rgb(100, 100, 100)", "rgb(200, 200, 200)"],
+  expected: "rgb(150, 150, 150)"
+}, 'Animating a custom property of type <color>');
+
+animation_test({
+  syntax: "<color>",
+  inherits: false,
+  initialValue: "rgb(100, 100, 100)"
+}, {
+  keyframes: "rgb(200, 200, 200)",
+  expected: "rgb(150, 150, 150)"
+}, 'Animating a custom property of type <color> with a single keyframe');
+
+animation_test({
+  syntax: "<color>",
+  inherits: false,
+  initialValue: "rgb(100, 100, 100)"
+}, {
+  composite: "add",
+  keyframes: ["rgb(50, 50, 50)", "rgb(150, 150, 150)"],
+  expected: "rgb(200, 200, 200)"
+}, 'Animating a custom property of type <color> with additivity');
+
+animation_test({
+  syntax: "<color>",
+  inherits: false,
+  initialValue: "rgb(100, 100, 100)"
+}, {
+  composite: "add",
+  keyframes: "rgb(150, 150, 150)",
+  expected: "rgb(175, 175, 175)"
+}, 'Animating a custom property of type <color> with a single keyframe and additivity');
+
+animation_test({
+  syntax: "<color>",
+  inherits: false,
+  initialValue: "black"
+}, {
+  iterationComposite: "accumulate",
+  keyframes: ["rgb(0, 0, 0)", "rgb(100, 100, 100)"],
+  expected: "rgb(250, 250, 250)"
+}, 'Animating a custom property of type <color> with iterationComposite');
+
+</script>
diff --git a/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-custom-ident.html b/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-custom-ident.html
new file mode 100644
index 00000000000..3f210f914b3
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-custom-ident.html
@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<link rel="help" href="https://drafts.css-houdini.org/css-properties-values-api-1">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../resources/utils.js"></script>
+<div id="target"></div>
+<script>
+
+discrete_animation_test("<custom-ident>", "from", "to");
+
+</script>
diff --git a/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-image.html b/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-image.html
new file mode 100644
index 00000000000..935d3025d4a
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-image.html
@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<link rel="help" href="https://drafts.css-houdini.org/css-properties-values-api-1">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../resources/utils.js"></script>
+<div id="target"></div>
+<script>
+
+discrete_animation_test("<image>", 'url("https://example.com/from")', 'url("https://example.com/to")');
+
+</script>
diff --git a/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-inherited-used-by-standard-property.html b/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-inherited-used-by-standard-property.html
new file mode 100644
index 00000000000..231ecca8c79
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-inherited-used-by-standard-property.html
@@ -0,0 +1,29 @@
+<!DOCTYPE html>
+<link rel="help" href="https://drafts.css-houdini.org/css-properties-values-api-1">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../resources/utils.js"></script>
+<div id="container">
+    <div id="target"></div>
+</div>
+<script>
+
+test(() => {
+  CSS.registerProperty({
+    name: "--my-length",
+    syntax: "<length>",
+    inherits: true,
+    initialValue: "0px"
+  });
+
+  target.style.marginLeft = "var(--my-length)";
+
+  const duration = 1000;
+  const animation = container.animate({ "--my-length": "100px" }, duration);
+  animation.pause();
+  animation.currentTime = duration / 4;
+
+  assert_equals(getComputedStyle(target).marginLeft, "25px");
+}, "Animating an inherited CSS variable on a parent is reflected on a standard property using that variable as a value on a child");
+
+</script>
\ No newline at end of file
diff --git a/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-integer.html b/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-integer.html
new file mode 100644
index 00000000000..400308a92ea
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-integer.html
@@ -0,0 +1,57 @@
+<!DOCTYPE html>
+<link rel="help" href="https://drafts.css-houdini.org/css-properties-values-api-1">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../resources/utils.js"></script>
+<div id="target"></div>
+<script>
+
+animation_test({
+  syntax: "<integer>",
+  inherits: false,
+  initialValue: 0
+}, {
+  keyframes: [100, 200],
+  expected: "150"
+}, 'Animating a custom property of type <integer>');
+
+animation_test({
+  syntax: "<integer>",
+  inherits: false,
+  initialValue: 100
+}, {
+  keyframes: 200,
+  expected: "150"
+}, 'Animating a custom property of type <integer> with a single keyframe');
+
+animation_test({
+  syntax: "<integer>",
+  inherits: false,
+  initialValue: 100
+}, {
+  composite: "add",
+  keyframes: [200, 300],
+  expected: "350"
+}, 'Animating a custom property of type <integer> with additivity');
+
+animation_test({
+  syntax: "<integer>",
+  inherits: false,
+  initialValue: 100
+}, {
+  composite: "add",
+  keyframes: 300,
+  expected: "250"
+}, 'Animating a custom property of type <integer> with a single keyframe and additivity');
+
+animation_test({
+  syntax: "<integer>",
+  inherits: false,
+  initialValue: 100
+}, {
+  iterationComposite: "accumulate",
+  keyframes: [0, 100],
+  expected: "250"
+}, 'Animating a custom property of type <integer> with iterationComposite');
+
+</script>
diff --git a/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-length-percentage.html b/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-length-percentage.html
new file mode 100644
index 00000000000..096efd6ba7f
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-length-percentage.html
@@ -0,0 +1,57 @@
+<!DOCTYPE html>
+<link rel="help" href="https://drafts.css-houdini.org/css-properties-values-api-1">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../resources/utils.js"></script>
+<div id="target"></div>
+<script>
+
+animation_test({
+  syntax: "<length-percentage>",
+  inherits: false,
+  initialValue: "0px"
+}, {
+  keyframes: ["100px", "100%"],
+  expected: "calc(50% + 50px)"
+}, 'Animating a custom property of type <length-percentage>');
+
+animation_test({
+  syntax: "<length-percentage>",
+  inherits: false,
+  initialValue: "100px"
+}, {
+  keyframes: "100%",
+  expected: "calc(50% + 50px)"
+}, 'Animating a custom property of type <length-percentage> with a single keyframe');
+
+animation_test({
+  syntax: "<length-percentage>",
+  inherits: false,
+  initialValue: "100px"
+}, {
+  composite: "add",
+  keyframes: ["200%", "300%"],
+  expected: "calc(250% + 100px)"
+}, 'Animating a custom property of type <length-percentage> with additivity');
+
+animation_test({
+  syntax: "<length-percentage>",
+  inherits: false,
+  initialValue: "100px"
+}, {
+  composite: "add",
+  keyframes: "300%",
+  expected: "calc(150% + 100px)"
+}, 'Animating a custom property of type <length-percentage> with a single keyframe and additivity');
+
+animation_test({
+  syntax: "<length-percentage>",
+  inherits: false,
+  initialValue: "100px"
+}, {
+  iterationComposite: "accumulate",
+  keyframes: ["50px", "100%"],
+  expected: "calc(250% + 25px)"
+}, 'Animating a custom property of type <length-percentage> with iterationComposite');
+
+</script>
diff --git a/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-length.html b/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-length.html
new file mode 100644
index 00000000000..8849bf52d66
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-length.html
@@ -0,0 +1,57 @@
+<!DOCTYPE html>
+<link rel="help" href="https://drafts.css-houdini.org/css-properties-values-api-1">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../resources/utils.js"></script>
+<div id="target"></div>
+<script>
+
+animation_test({
+  syntax: "<length>",
+  inherits: false,
+  initialValue: "0px"
+}, {
+  keyframes: ["100px", "200px"],
+  expected: "150px"
+}, 'Animating a custom property of type <length>');
+
+animation_test({
+  syntax: "<length>",
+  inherits: false,
+  initialValue: "100px"
+}, {
+  keyframes: "200px",
+  expected: "150px"
+}, 'Animating a custom property of type <length> with a single keyframe');
+
+animation_test({
+  syntax: "<length>",
+  inherits: false,
+  initialValue: "100px"
+}, {
+  composite: "add",
+  keyframes: ["200px", "300px"],
+  expected: "350px"
+}, 'Animating a custom property of type <length> with additivity');
+
+animation_test({
+  syntax: "<length>",
+  inherits: false,
+  initialValue: "100px"
+}, {
+  composite: "add",
+  keyframes: "300px",
+  expected: "250px"
+}, 'Animating a custom property of type <length> with a single keyframe and additivity');
+
+animation_test({
+  syntax: "<length>",
+  inherits: false,
+  initialValue: "100px"
+}, {
+  iterationComposite: "accumulate",
+  keyframes: ["0px", "100px"],
+  expected: "250px"
+}, 'Animating a custom property of type <length> with iterationComposite');
+
+</script>
diff --git a/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-non-inherited-used-by-standard-property.html b/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-non-inherited-used-by-standard-property.html
new file mode 100644
index 00000000000..11d3f6740d9
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-non-inherited-used-by-standard-property.html
@@ -0,0 +1,27 @@
+<!DOCTYPE html>
+<link rel="help" href="https://drafts.css-houdini.org/css-properties-values-api-1">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../resources/utils.js"></script>
+<div id="target"></div>
+<script>
+
+test(() => {
+  CSS.registerProperty({
+    name: "--my-length",
+    syntax: "<length>",
+    inherits: false,
+    initialValue: "0px"
+  });
+
+  target.style.marginLeft = "var(--my-length)";
+
+  const duration = 1000;
+  const animation = target.animate({ "--my-length": "100px" }, duration);
+  animation.pause();
+  animation.currentTime = duration / 4;
+
+  assert_equals(getComputedStyle(target).marginLeft, "25px");
+}, "Animating a non-inherited CSS variable is reflected on a standard property using that variable as a value");
+
+</script>
\ No newline at end of file
diff --git a/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-number.html b/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-number.html
new file mode 100644
index 00000000000..ea28acacf68
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-number.html
@@ -0,0 +1,57 @@
+<!DOCTYPE html>
+<link rel="help" href="https://drafts.css-houdini.org/css-properties-values-api-1">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../resources/utils.js"></script>
+<div id="target"></div>
+<script>
+
+animation_test({
+  syntax: "<number>",
+  inherits: false,
+  initialValue: 0
+}, {
+  keyframes: [100, 200],
+  expected: "150"
+}, 'Animating a custom property of type <number>');
+
+animation_test({
+  syntax: "<number>",
+  inherits: false,
+  initialValue: 100
+}, {
+  keyframes: 200,
+  expected: "150"
+}, 'Animating a custom property of type <number> with a single keyframe');
+
+animation_test({
+  syntax: "<number>",
+  inherits: false,
+  initialValue: 100
+}, {
+  composite: "add",
+  keyframes: [200, 300],
+  expected: "350"
+}, 'Animating a custom property of type <number> with additivity');
+
+animation_test({
+  syntax: "<number>",
+  inherits: false,
+  initialValue: 100
+}, {
+  composite: "add",
+  keyframes: 300,
+  expected: "250"
+}, 'Animating a custom property of type <number> with a single keyframe and additivity');
+
+animation_test({
+  syntax: "<number>",
+  inherits: false,
+  initialValue: 100
+}, {
+  iterationComposite: "accumulate",
+  keyframes: [0, 100],
+  expected: "250"
+}, 'Animating a custom property of type <number> with iterationComposite');
+
+</script>
diff --git a/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-percentage.html b/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-percentage.html
new file mode 100644
index 00000000000..6af498e7025
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-percentage.html
@@ -0,0 +1,57 @@
+<!DOCTYPE html>
+<link rel="help" href="https://drafts.css-houdini.org/css-properties-values-api-1">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../resources/utils.js"></script>
+<div id="target"></div>
+<script>
+
+animation_test({
+  syntax: "<percentage>",
+  inherits: false,
+  initialValue: "0%"
+}, {
+  keyframes: ["100%", "200%"],
+  expected: "150%"
+}, 'Animating a custom property of type <percentage>');
+
+animation_test({
+  syntax: "<percentage>",
+  inherits: false,
+  initialValue: "100%"
+}, {
+  keyframes: "200%",
+  expected: "150%"
+}, 'Animating a custom property of type <percentage> with a single keyframe');
+
+animation_test({
+  syntax: "<percentage>",
+  inherits: false,
+  initialValue: "100%"
+}, {
+  composite: "add",
+  keyframes: ["200%", "300%"],
+  expected: "350%"
+}, 'Animating a custom property of type <percentage> with additivity');
+
+animation_test({
+  syntax: "<percentage>",
+  inherits: false,
+  initialValue: "100%"
+}, {
+  composite: "add",
+  keyframes: "300%",
+  expected: "250%"
+}, 'Animating a custom property of type <percentage> with a single keyframe and additivity');
+
+animation_test({
+  syntax: "<percentage>",
+  inherits: false,
+  initialValue: "100%"
+}, {
+  iterationComposite: "accumulate",
+  keyframes: ["0%", "100%"],
+  expected: "250%"
+}, 'Animating a custom property of type <percentage> with iterationComposite');
+
+</script>
diff --git a/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-resolution.html b/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-resolution.html
new file mode 100644
index 00000000000..3d05139edca
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-resolution.html
@@ -0,0 +1,57 @@
+<!DOCTYPE html>
+<link rel="help" href="https://drafts.css-houdini.org/css-properties-values-api-1">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../resources/utils.js"></script>
+<div id="target"></div>
+<script>
+
+animation_test({
+  syntax: "<resolution>",
+  inherits: false,
+  initialValue: "0dppx"
+}, {
+  keyframes: ["100dppx", "200dppx"],
+  expected: "150dppx"
+}, 'Animating a custom property of type <resolution>');
+
+animation_test({
+  syntax: "<resolution>",
+  inherits: false,
+  initialValue: "100dppx"
+}, {
+  keyframes: "200dppx",
+  expected: "150dppx"
+}, 'Animating a custom property of type <resolution> with a single keyframe');
+
+animation_test({
+  syntax: "<resolution>",
+  inherits: false,
+  initialValue: "100dppx"
+}, {
+  composite: "add",
+  keyframes: ["200dppx", "300dppx"],
+  expected: "350dppx"
+}, 'Animating a custom property of type <resolution> with additivity');
+
+animation_test({
+  syntax: "<resolution>",
+  inherits: false,
+  initialValue: "100dppx"
+}, {
+  composite: "add",
+  keyframes: "300dppx",
+  expected: "250dppx"
+}, 'Animating a custom property of type <resolution> with a single keyframe and additivity');
+
+animation_test({
+  syntax: "<resolution>",
+  inherits: false,
+  initialValue: "100dppx"
+}, {
+  iterationComposite: "accumulate",
+  keyframes: ["0dppx", "100dppx"],
+  expected: "250dppx"
+}, 'Animating a custom property of type <resolution> with iterationComposite');
+
+</script>
diff --git a/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-time.html b/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-time.html
new file mode 100644
index 00000000000..b9f5984db7c
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-time.html
@@ -0,0 +1,57 @@
+<!DOCTYPE html>
+<link rel="help" href="https://drafts.css-houdini.org/css-properties-values-api-1">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../resources/utils.js"></script>
+<div id="target"></div>
+<script>
+
+animation_test({
+  syntax: "<time>",
+  inherits: false,
+  initialValue: "0s"
+}, {
+  keyframes: ["100s", "200s"],
+  expected: "150s"
+}, 'Animating a custom property of type <time>');
+
+animation_test({
+  syntax: "<time>",
+  inherits: false,
+  initialValue: "100s"
+}, {
+  keyframes: "200s",
+  expected: "150s"
+}, 'Animating a custom property of type <time> with a single keyframe');
+
+animation_test({
+  syntax: "<time>",
+  inherits: false,
+  initialValue: "100s"
+}, {
+  composite: "add",
+  keyframes: ["200s", "300s"],
+  expected: "350s"
+}, 'Animating a custom property of type <time> with additivity');
+
+animation_test({
+  syntax: "<time>",
+  inherits: false,
+  initialValue: "100s"
+}, {
+  composite: "add",
+  keyframes: "300s",
+  expected: "250s"
+}, 'Animating a custom property of type <time> with a single keyframe and additivity');
+
+animation_test({
+  syntax: "<time>",
+  inherits: false,
+  initialValue: "100s"
+}, {
+  iterationComposite: "accumulate",
+  keyframes: ["0s", "100s"],
+  expected: "250s"
+}, 'Animating a custom property of type <time> with iterationComposite');
+
+</script>
diff --git a/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-url.html b/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-url.html
new file mode 100644
index 00000000000..00ea48557fe
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-properties-values-api/animation/custom-property-animation-url.html
@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<link rel="help" href="https://drafts.css-houdini.org/css-properties-values-api-1">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../resources/utils.js"></script>
+<div id="target"></div>
+<script>
+
+discrete_animation_test("<url>", 'url("https://example.com/from")', 'url("https://example.com/to")');
+
+</script>
diff --git a/tests/wpt/web-platform-tests/css/css-properties-values-api/resources/utils.js b/tests/wpt/web-platform-tests/css/css-properties-values-api/resources/utils.js
index fca6093471d..c9a0c73828f 100644
--- a/tests/wpt/web-platform-tests/css/css-properties-values-api/resources/utils.js
+++ b/tests/wpt/web-platform-tests/css/css-properties-values-api/resources/utils.js
@@ -124,3 +124,57 @@ function test_with_at_property(desc, fn, description) {
 function test_with_style_node(text, fn, description) {
   test(() => with_style_node(text, fn), description);
 }
+
+function animation_test(property, values, description) {
+  const name = generate_name();
+  property.name = name;
+  CSS.registerProperty(property);
+
+  test(() => {
+    const duration = 1000;
+    const keyframes = {};
+    keyframes[name] = values.keyframes;
+
+    const iterations = 3;
+    const composite = values.composite || "replace";
+    const iterationComposite = values.iterationComposite || "replace";
+    const animation = target.animate(keyframes, { composite, iterationComposite, iterations, duration });
+    animation.pause();
+    // We seek to the middle of the third iteration which will allow to test cases where
+    // iterationComposite is set to something other than "replace".
+    animation.currentTime = duration * 2.5;
+
+    assert_equals(getComputedStyle(target).getPropertyValue(name), values.expected);
+  }, description);
+};
+
+function discrete_animation_test(syntax, fromValue, toValue) {
+  test(() => {
+    const name = generate_name();
+
+    CSS.registerProperty({
+      name,
+      syntax,
+      inherits: false,
+      initialValue: fromValue
+    });
+
+    const duration = 1000;
+    const keyframes = [];
+    keyframes[name] = toValue;
+    const animation = target.animate(keyframes, duration);
+    animation.pause();
+
+    const checkAtProgress = (progress, expected) => {
+      animation.currentTime = duration * 0.25;
+      assert_equals(getComputedStyle(target).getPropertyValue(name), fromValue, `The correct value is used at progress = ${progress}`);
+    };
+
+    checkAtProgress(0, fromValue);
+    checkAtProgress(0.25, fromValue);
+    checkAtProgress(0.49, fromValue);
+    checkAtProgress(0.5, toValue);
+    checkAtProgress(0.75, toValue);
+    checkAtProgress(1, toValue);
+  }, `Animating a custom property of type ${syntax} is discrete`);
+}
diff --git a/tests/wpt/web-platform-tests/css/css-typed-om/stylevalue-serialization/cssTransformValue.tentative.html b/tests/wpt/web-platform-tests/css/css-typed-om/stylevalue-serialization/cssTransformValue.tentative.html
index e313647fa56..856b9314d85 100644
--- a/tests/wpt/web-platform-tests/css/css-typed-om/stylevalue-serialization/cssTransformValue.tentative.html
+++ b/tests/wpt/web-platform-tests/css/css-typed-om/stylevalue-serialization/cssTransformValue.tentative.html
@@ -129,7 +129,7 @@ const gTestCases = [
               new CSSUnitValue(0, 'number')))
         )
       ]),
-    cssText:'rotate3d(0, 0, 0, calc(1deg * (1 / 0)))',
+    cssText:'rotate3d(0, 0, 0, calc(1deg / 0))',
     desc: 'CSSMathInvert with 0 parameter and nested'
   },
   {
diff --git a/tests/wpt/web-platform-tests/css/css-typed-om/the-stylepropertymap/properties/resources/testsuite.js b/tests/wpt/web-platform-tests/css/css-typed-om/the-stylepropertymap/properties/resources/testsuite.js
index a365f001316..2c0df9110d0 100644
--- a/tests/wpt/web-platform-tests/css/css-typed-om/the-stylepropertymap/properties/resources/testsuite.js
+++ b/tests/wpt/web-platform-tests/css/css-typed-om/the-stylepropertymap/properties/resources/testsuite.js
@@ -349,12 +349,12 @@ function testIsImageValidForProperty(propertyName) {
 
 // Test that styleMap.set throws for invalid values
 function testPropertyInvalid(propertyName, examples, description) {
-  test(t => {
-    let styleMap = createInlineStyleMap(t);
-    for (const example of examples) {
+  for (const example of examples) {
+    test(t => {
+      let styleMap = createInlineStyleMap(t);
       assert_throws_js(TypeError, () => styleMap.set(propertyName, example.input));
-    }
-  }, `Setting '${propertyName}' to ${description} throws TypeError`);
+    }, `Setting '${propertyName}' to ${description}: ${example.input} throws TypeError`);
+  }
 }
 
 // Test that styleMap.get/.set roundtrips correctly for unsupported values.
@@ -378,7 +378,7 @@ function testUnsupportedValue(propertyName, cssText) {
     assert_style_value_equals(resultAll[0], result,
       `getAll() with single unsupported value returns single-item list ` +
       `with same result as get()`);
-  }, `'${propertyName}' does not supported '${cssText}'`);
+  }, `'${propertyName}' does not support '${cssText}'`);
 }
 
 function createKeywordExample(keyword) {
diff --git a/tests/wpt/web-platform-tests/css/cssom/CSSFontFeatureValuesRule.html b/tests/wpt/web-platform-tests/css/cssom/CSSFontFeatureValuesRule.html
index a267675cbad..a0ea64a5038 100644
--- a/tests/wpt/web-platform-tests/css/cssom/CSSFontFeatureValuesRule.html
+++ b/tests/wpt/web-platform-tests/css/cssom/CSSFontFeatureValuesRule.html
@@ -5,34 +5,49 @@
   rel="help"
   href="https://drafts.csswg.org/css-fonts-4/#om-fontfeaturevalues"
 />
-<link rel="author" title="Dominik Röttsches" href="drott@chromium.org">
-<meta name="assert" content="CSSFontFeatureValuesRule interface is accessible and supports read and write access.">
+<link rel="author" title="Dominik Röttsches" href="drott@chromium.org" />
+<meta
+  name="assert"
+  content="CSSFontFeatureValuesRule interface is accessible and supports read and write access."
+/>
 <script src="/resources/testharness.js"></script>
 <script src="/resources/testharnessreport.js"></script>
 <style></style>
+<body></body>
 <script>
   let rule_initial = `
-@font-feature-values test_family {
-  @annotation {
-    the_first: 6;
+  @font-feature-values test_family {
+    @annotation {
+      the_first: 6;
+    }
+    @styleset {
+      yo: 7;
+      del: 4;
+      di: 10 9 4 5;
+    }
   }
-  @styleset {
-    yo: 7;
-    del: 4;
-    di: 10 9 4 5;
-  }
-}
-`;
+  `;
 
   let rule_added = `
-@font-feature-values second_family {
-  @annotation {
-    yabab: 2;
-    yogog: 4;
-    bidib: 5;
+  @font-feature-values second_family {
+    @annotation {
+      yabab: 2;
+      yogog: 4;
+      bidib: 5;
+    }
   }
-}
-`;
+  `;
+
+  let rule_overlap = `
+  @font-feature-values test_family {
+    @annotation {
+      baric: 17;
+    }
+    @ornaments {
+      fooic: 1;
+    }
+  }
+  `;
 
   function resetStateAndTest(testFunction) {
     var sheet = document.styleSheets[0];
@@ -133,4 +148,45 @@
       assert_equals(document.styleSheets[0].cssRules[1].annotation.size, 0);
     });
   }, "Clearing all entries is possible.");
+
+  test(function () {
+    resetStateAndTest(() => {
+      assert_equals(document.styleSheets[0].cssRules.length, 1);
+      document.styleSheets[0].insertRule(rule_overlap, 1);
+      assert_equals(document.styleSheets[0].cssRules.length, 2);
+
+      // Force updating internal state.
+      getComputedStyle(document.body).borderTop;
+
+      assert_equals(
+        document.styleSheets[0].cssRules[0].annotation.size,
+        1,
+        "1 annotation."
+      );
+      assert_equals(
+        document.styleSheets[0].cssRules[0].styleset.size,
+        3,
+        "3 entries in styleset."
+      );
+      assert_equals(
+        document.styleSheets[0].cssRules[0].ornaments.size,
+        0,
+        "No ornament entries."
+      );
+      assert_false(
+        document.styleSheets[0].cssRules[0].annotation.has("baric"),
+        "Annotation must not contain 'baric'."
+      );
+      assert_false(
+        document.styleSheets[0].cssRules[0].ornaments.has("fooic"),
+        "Ornaments must not contain 'fooic'."
+      );
+
+      assert_equals(document.styleSheets[0].cssRules[1].annotation.size, 1);
+      assert_equals(document.styleSheets[0].cssRules[1].ornaments.size, 1);
+      assert_false(
+        document.styleSheets[0].cssRules[1].annotation.has("the_first")
+      );
+    });
+  }, "Multiple rules for the same family are kept separate in CSSOM.");
 </script>
diff --git a/tests/wpt/web-platform-tests/fullscreen/rendering/fullscreen-root-fills-page-ref.html b/tests/wpt/web-platform-tests/fullscreen/rendering/fullscreen-root-fills-page-ref.html
new file mode 100644
index 00000000000..b2bf13557a2
--- /dev/null
+++ b/tests/wpt/web-platform-tests/fullscreen/rendering/fullscreen-root-fills-page-ref.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<html>
+<head>
+    <style>
+        html, body {
+            width: 100%;
+            height: 100%;
+            margin: 0;
+            padding: 0;
+        }
+
+        body {
+            background-color: green;
+        }
+    </style>
+</head>
+<body></body>
+</html>
diff --git a/tests/wpt/web-platform-tests/fullscreen/rendering/fullscreen-root-fills-page.html b/tests/wpt/web-platform-tests/fullscreen/rendering/fullscreen-root-fills-page.html
new file mode 100644
index 00000000000..f122e678f3f
--- /dev/null
+++ b/tests/wpt/web-platform-tests/fullscreen/rendering/fullscreen-root-fills-page.html
@@ -0,0 +1,47 @@
+<!DOCTYPE html>
+<html class="reftest-wait">
+<head>
+    <link rel="author" href="https://github.com/nt1m">
+    <link rel="match" href="fullscreen-root-fills-page-ref.html">
+    <style>
+        html {
+            background-color: red;
+            height: 100%;
+            overflow: hidden;
+
+            /* These should be no-op */
+            top: 200px;
+            left: 200px;
+            right: 200px;
+            bottom: 200px;
+        }
+
+        html, body {
+            margin: 0;
+            padding: 0;
+        }
+
+        body, #cover {
+            height: 100%;
+            width: 100%;
+        }
+
+        #cover {
+            background-color: green;
+        }
+    </style>
+</head>
+
+<body>
+    <div id="cover"></div>
+    <script src="/resources/testdriver.js"></script>
+    <script src="/resources/testdriver-vendor.js"></script>
+    <script>
+        document.addEventListener("fullscreenchange", () => {
+            document.documentElement.classList.remove("reftest-wait");
+        });
+        test_driver.bless("fullscreen")
+            .then(() => document.documentElement.requestFullscreen())
+    </script>
+</body>
+</html>
diff --git a/tests/wpt/web-platform-tests/generic-sensor/resources/iframe_sensor_handler.html b/tests/wpt/web-platform-tests/generic-sensor/resources/iframe_sensor_handler.html
index 23e8e1bb94d..4528c57a6be 100644
--- a/tests/wpt/web-platform-tests/generic-sensor/resources/iframe_sensor_handler.html
+++ b/tests/wpt/web-platform-tests/generic-sensor/resources/iframe_sensor_handler.html
@@ -21,10 +21,13 @@
         return Promise.reject('"create_sensor" must be called first');
       }
 
-      return new Promise(resolve => {
+      return new Promise((resolve, reject) => {
         sensor.addEventListener('reading', () => {
           resolve('success');
         }, { once: true });
+        sensor.addEventListener('error', e => {
+          reject(`${e.error.name}: ${e.error.message}`);
+        }, { once: true });
         sensor.start();
       });
     } else if (e.data.command === 'is_sensor_suspended') {
diff --git a/tests/wpt/web-platform-tests/html/semantics/forms/the-input-element/password-delete-space.html b/tests/wpt/web-platform-tests/html/semantics/forms/the-input-element/password-delete-space.html
new file mode 100644
index 00000000000..78b3c966b80
--- /dev/null
+++ b/tests/wpt/web-platform-tests/html/semantics/forms/the-input-element/password-delete-space.html
@@ -0,0 +1,20 @@
+<!DOCTYPE html>
+<title>Backspace with trailing white space in password field</title>
+<link rel="help" href="https://bugs.chromium.org/p/chromium/issues/detail?id=1400844">
+<link rel="help" href="https://html.spec.whatwg.org/multipage/#password-state-%28type=password%29">
+<link rel="author" href="mailto:xiaochengh@chromium.org">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+
+<input id="target" type="password" value="   ">
+
+<script>
+promise_test(async () => {
+  target.focus();
+  target.selectionStart = 2;
+  await test_driver.send_keys(target, '\uE003');
+  assert_equals(target.value, "  ");
+}, "Backspace with trailing white space in password field");
+</script>
diff --git a/tests/wpt/web-platform-tests/html/semantics/popovers/popover-light-dismiss.tentative.html b/tests/wpt/web-platform-tests/html/semantics/popovers/popover-light-dismiss.tentative.html
index bdd0d12545f..83573c86f06 100644
--- a/tests/wpt/web-platform-tests/html/semantics/popovers/popover-light-dismiss.tentative.html
+++ b/tests/wpt/web-platform-tests/html/semantics/popovers/popover-light-dismiss.tentative.html
@@ -242,13 +242,9 @@
     popover1.showPopover();
     assert_true(popover1.matches(':open'));
     await waitForRender();
-    p1HideCount = popover1HideCount;
     await clickOn(popover1anchor);
-    assert_true(popover1.matches(':open'),'popover1 not open');
-    assert_equals(popover1HideCount,p1HideCount);
-    popover1.hidePopover(); // Cleanup
-    assert_false(popover1.matches(':open'));
-  },'Clicking on anchor element (that isn\'t an invoking element) shouldn\'t close its popover');
+    assert_false(popover1.matches(':open'),'popover1 should close');
+  },'Clicking on anchor element (that isn\'t an invoking element) shouldn\'t prevent its popover from being closed');
 
   promise_test(async () => {
     popover1.showPopover();
@@ -273,9 +269,9 @@
   <div popover id=p4>Inside popover 4</div>
 </button>
 <div popover id=p3>Inside popover 3</div>
-<button id=b4 popovertoggletarget=p3>Popover 3 - button 4
-  <div popover id=p5>Inside popover 5</div>
-</button>
+<div popover id=p5>Inside popover 5
+  <button popovertoggletarget=p3>Popover 3 - button 4 - unused</button>
+</div>
 <style>
   #p3 {top:100px;}
   #p4 {top:200px;}
@@ -291,24 +287,20 @@
     assert_true(popover3.matches(':open'),'invoking element should open popover');
     popover4.showPopover();
     assert_true(popover4.matches(':open'));
-    assert_true(popover3.matches(':open'));
-    popover3.hidePopover(); // Cleanup
-    assert_false(popover3.matches(':open'));
+    assert_false(popover3.matches(':open'),'popover3 is unrelated to popover4');
+    popover4.hidePopover(); // Cleanup
     assert_false(popover4.matches(':open'));
-  },'An invoking element should be part of the ancestor chain');
+  },'A popover inside an invoking element doesn\'t participate in that invoker\'s ancestor chain');
 
   promise_test(async () => {
-    await clickOn(button3);
-    assert_true(popover3.matches(':open'));
-    assert_false(popover4.matches(':open'));
-    assert_false(popover5.matches(':open'));
     popover5.showPopover();
-    assert_true(popover3.matches(':open'));
-    assert_false(popover4.matches(':open'));
     assert_true(popover5.matches(':open'));
-    popover3.hidePopover();
     assert_false(popover3.matches(':open'));
-    assert_false(popover4.matches(':open'));
+    popover3.showPopover();
+    assert_true(popover3.matches(':open'));
+    assert_true(popover5.matches(':open'));
+    popover5.hidePopover();
+    assert_false(popover3.matches(':open'));
     assert_false(popover5.matches(':open'));
   },'An invoking element that was not used to invoke the popover can still be part of the ancestor chain');
 </script>
diff --git a/tests/wpt/web-platform-tests/performance-timeline/resources/parent-frame-with-child.sub.html b/tests/wpt/web-platform-tests/performance-timeline/resources/parent-frame-with-cross-origin-child.sub.html
similarity index 67%
rename from tests/wpt/web-platform-tests/performance-timeline/resources/parent-frame-with-child.sub.html
rename to tests/wpt/web-platform-tests/performance-timeline/resources/parent-frame-with-cross-origin-child.sub.html
index 32dd4cb48bc..4be0df872cb 100644
--- a/tests/wpt/web-platform-tests/performance-timeline/resources/parent-frame-with-child.sub.html
+++ b/tests/wpt/web-platform-tests/performance-timeline/resources/parent-frame-with-cross-origin-child.sub.html
@@ -2,6 +2,7 @@
 <head></head>
 <body></body>
 <script>
+    // Create child frame that is cross-origin with its parent.
     const childFrame = document.createElement('iframe')
     childFrame.src = "http://{{hosts[][]}}:{{ports[http][0]}}/performance-timeline/resources/child-frame.html"
     document.body.appendChild(childFrame)
@@ -9,6 +10,7 @@
     performance.mark("entry-name")
 
     childFrame.addEventListener('load', () => {
-        window.parent.postMessage("DONE", "*")
+        const entries = performance.getEntries(true)
+        window.parent.postMessage(entries.length, "*")
     })
 </script>
\ No newline at end of file
diff --git a/tests/wpt/web-platform-tests/performance-timeline/resources/parent-frame-with-same-origin-child.html b/tests/wpt/web-platform-tests/performance-timeline/resources/parent-frame-with-same-origin-child.html
new file mode 100644
index 00000000000..c9248a4e8bb
--- /dev/null
+++ b/tests/wpt/web-platform-tests/performance-timeline/resources/parent-frame-with-same-origin-child.html
@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+<head></head>
+<body></body>
+<script>
+    // Create child frame that is same-origin with its parent.
+    const childFrame = document.createElement('iframe')
+    childFrame.src = "child-frame.html"
+    document.body.appendChild(childFrame)
+
+    performance.mark("entry-name")
+
+    childFrame.addEventListener('load', () => {
+        const entries = performance.getEntries(true)
+        window.parent.postMessage(entries.length, "*")
+    })
+</script>
\ No newline at end of file
diff --git a/tests/wpt/web-platform-tests/performance-timeline/tentative/include-frames-from-child-cross-origin-grandchild.sub.html b/tests/wpt/web-platform-tests/performance-timeline/tentative/include-frames-from-child-cross-origin-grandchild.sub.html
new file mode 100644
index 00000000000..1886f040ec6
--- /dev/null
+++ b/tests/wpt/web-platform-tests/performance-timeline/tentative/include-frames-from-child-cross-origin-grandchild.sub.html
@@ -0,0 +1,32 @@
+<!DOCTYPE html>
+<head>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+</body>
+<script>
+promise_test(() => {
+    return new Promise(resolve => {
+        performance.clearResourceTimings()
+
+        // Create child iframe with an embedded frame that is same-origin with its parent but cross-origin with the current frame.
+        const crossOriginChildFrame = document.createElement('iframe')
+        crossOriginChildFrame.src = "http://{{hosts[][www]}}:{{ports[http][0]}}/performance-timeline/resources/parent-frame-with-same-origin-child.html"
+        document.body.appendChild(crossOriginChildFrame)
+
+        // Listen for postMessage() from child frame.
+        window.addEventListener("message", e => {
+            // 0 entries for parent, 4 for child, 2 for grandchild.
+            assert_equals(e.data, 6)
+
+            const entries = performance.getEntries(true)
+
+            // 3 entries for parent, 0 for child, 0 for grandchild.
+            assert_equals(entries.length, 3)
+
+            resolve()
+        })
+    })
+}, "GetEntries of a Cross-Origin child frame with one Cross-Origin grandchild frame")
+</script>
\ No newline at end of file
diff --git a/tests/wpt/web-platform-tests/performance-timeline/tentative/include-frames-from-child-same-origin-grandchild.sub.html b/tests/wpt/web-platform-tests/performance-timeline/tentative/include-frames-from-child-same-origin-grandchild.sub.html
new file mode 100644
index 00000000000..16142ca953a
--- /dev/null
+++ b/tests/wpt/web-platform-tests/performance-timeline/tentative/include-frames-from-child-same-origin-grandchild.sub.html
@@ -0,0 +1,32 @@
+<!DOCTYPE html>
+<head>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+</body>
+<script>
+promise_test(() => {
+    return new Promise(resolve => {
+        performance.clearResourceTimings()
+
+        // Create child iframe with an embedded frame that is cross-origin with its parent but same-origin with the current frame.
+        const crossOriginChildFrame = document.createElement('iframe')
+        crossOriginChildFrame.src = "http://{{hosts[][www]}}:{{ports[http][0]}}/performance-timeline/resources/parent-frame-with-cross-origin-child.sub.html"
+        document.body.appendChild(crossOriginChildFrame)
+
+        // Listen for postMessage() from child frame.
+        window.addEventListener("message", e => {
+            // 0 entries for parent, 4 for child, 0 for grandchild.
+            assert_equals(e.data, 4)
+
+            const entries = performance.getEntries(true)
+
+            // 3 entries for parent, 0 for child, 2 for grandchild.
+            assert_equals(entries.length, 5)
+
+            resolve()
+        })
+    })
+}, "GetEntries of a Cross-Origin child frame with one Same-Origin grandchild frame")
+</script>
\ No newline at end of file
diff --git a/tests/wpt/web-platform-tests/performance-timeline/tentative/include-frames-one-remote-child-one-local-grandchild.sub.html b/tests/wpt/web-platform-tests/performance-timeline/tentative/include-frames-one-cross-origin-child-one-same-origin-grandchild.sub.html
similarity index 65%
rename from tests/wpt/web-platform-tests/performance-timeline/tentative/include-frames-one-remote-child-one-local-grandchild.sub.html
rename to tests/wpt/web-platform-tests/performance-timeline/tentative/include-frames-one-cross-origin-child-one-same-origin-grandchild.sub.html
index a9efe414616..8aa5df778fe 100644
--- a/tests/wpt/web-platform-tests/performance-timeline/tentative/include-frames-one-remote-child-one-local-grandchild.sub.html
+++ b/tests/wpt/web-platform-tests/performance-timeline/tentative/include-frames-one-cross-origin-child-one-same-origin-grandchild.sub.html
@@ -10,10 +10,10 @@ promise_test(() => {
     return new Promise(resolve => {
         performance.clearResourceTimings()
 
-        // Create child iframe.
-        const remoteChildFrame = document.createElement('iframe')
-        remoteChildFrame.src = "http://{{hosts[][www]}}:{{ports[http][0]}}/performance-timeline/resources/parent-frame-with-child.sub.html"
-        document.body.appendChild(remoteChildFrame)
+        // Create child iframe with an embedded frame that is cross-origin with its parent, but same-origin with the current frame.
+        const crossOriginChildFrame = document.createElement('iframe')
+        crossOriginChildFrame.src = "http://{{hosts[][www]}}:{{ports[http][0]}}/performance-timeline/resources/parent-frame-with-cross-origin-child.sub.html"
+        document.body.appendChild(crossOriginChildFrame)
 
         // Listen for postMessage() from grandchild frame.
         window.addEventListener("message", () => {
@@ -33,5 +33,5 @@ promise_test(() => {
             resolve()
         })
     })
-}, "GetEntries of a ParentFrame with one RemoteFrame child and one LocalFrame grandchild")
+}, "GetEntries of a parent Frame with one Cross-Origin child and one Same-Origin grandchild")
 </script>
\ No newline at end of file
diff --git a/tests/wpt/web-platform-tests/performance-timeline/tentative/include-frames-one-remote-child.sub.html b/tests/wpt/web-platform-tests/performance-timeline/tentative/include-frames-one-remote-child.sub.html
index 822924c18b6..61e7a1f6480 100644
--- a/tests/wpt/web-platform-tests/performance-timeline/tentative/include-frames-one-remote-child.sub.html
+++ b/tests/wpt/web-platform-tests/performance-timeline/tentative/include-frames-one-remote-child.sub.html
@@ -32,5 +32,5 @@ promise_test(() => {
             resolve()
         })
     })
-}, "GetEntries of a ParentFrame with one RemoteFrame child")
+}, "GetEntries of a parent Frame with one Cross-Origin child")
 </script>
\ No newline at end of file
diff --git a/tests/wpt/web-platform-tests/performance-timeline/tentative/include-frames-one-local-child-one-remote-child.sub.html b/tests/wpt/web-platform-tests/performance-timeline/tentative/include-frames-one-same-origin-child-one-cross-origin-child.sub.html
similarity index 55%
rename from tests/wpt/web-platform-tests/performance-timeline/tentative/include-frames-one-local-child-one-remote-child.sub.html
rename to tests/wpt/web-platform-tests/performance-timeline/tentative/include-frames-one-same-origin-child-one-cross-origin-child.sub.html
index 8e1ca9774fa..b20bde93eed 100644
--- a/tests/wpt/web-platform-tests/performance-timeline/tentative/include-frames-one-local-child-one-remote-child.sub.html
+++ b/tests/wpt/web-platform-tests/performance-timeline/tentative/include-frames-one-same-origin-child-one-cross-origin-child.sub.html
@@ -10,28 +10,28 @@ promise_test(() => {
     return new Promise(resolve => {
         performance.clearResourceTimings()
 
-        let localFrameLoaded = false
-        let remoteFrameLoaded = false
+        let sameOriginFrameLoaded = false
+        let crossOriginFrameLoaded = false
 
         // Create first child iframe.
-        const localChildFrame = document.createElement('iframe')
-        localChildFrame.src = "../resources/child-frame.html"
-        document.body.appendChild(localChildFrame)
+        const sameOriginChildFrame = document.createElement('iframe')
+        sameOriginChildFrame.src = "../resources/child-frame.html"
+        document.body.appendChild(sameOriginChildFrame)
 
-        localChildFrame.addEventListener("load", () => {
-            localFrameLoaded = true
-            if (remoteFrameLoaded)
+        sameOriginChildFrame.addEventListener("load", () => {
+            sameOriginFrameLoaded = true
+            if (crossOriginFrameLoaded)
                 verifyPerformanceEntries()
         })
 
         // Create second child iframe.
-        const remoteChildFrame = document.createElement('iframe')
-        remoteChildFrame.src = "http://{{hosts[][www]}}:{{ports[http][0]}}/resources/child-frame.html"
-        document.body.appendChild(remoteChildFrame)
+        const crossOriginChildFrame = document.createElement('iframe')
+        crossOriginChildFrame.src = "http://{{hosts[][www]}}:{{ports[http][0]}}/resources/child-frame.html"
+        document.body.appendChild(crossOriginChildFrame)
 
-        remoteChildFrame.addEventListener("load", () => {
-            remoteFrameLoaded = true
-            if (localFrameLoaded)
+        crossOriginChildFrame.addEventListener("load", () => {
+            crossOriginFrameLoaded = true
+            if (sameOriginFrameLoaded)
                 verifyPerformanceEntries()
         })
 
@@ -52,5 +52,5 @@ promise_test(() => {
             resolve()
         }
     })
-}, "GetEntries of a ParentFrame with one RemoteFrame child and one LocalFrame child")
+}, "GetEntries of a parent Frame with one Cross-Origin child and one Same-Origin child")
 </script>
\ No newline at end of file
diff --git a/tests/wpt/web-platform-tests/performance-timeline/tentative/include-frames-one-local-child-one-local-grandchild.html b/tests/wpt/web-platform-tests/performance-timeline/tentative/include-frames-one-same-origin-child-one-same-origin-grandchild.html
similarity index 78%
rename from tests/wpt/web-platform-tests/performance-timeline/tentative/include-frames-one-local-child-one-local-grandchild.html
rename to tests/wpt/web-platform-tests/performance-timeline/tentative/include-frames-one-same-origin-child-one-same-origin-grandchild.html
index ee2dadde8f9..10ccea3da88 100644
--- a/tests/wpt/web-platform-tests/performance-timeline/tentative/include-frames-one-local-child-one-local-grandchild.html
+++ b/tests/wpt/web-platform-tests/performance-timeline/tentative/include-frames-one-same-origin-child-one-same-origin-grandchild.html
@@ -10,9 +10,9 @@ promise_test(() => {
     return new Promise(resolve => {
         performance.clearResourceTimings()
 
-        // Create child iframe.
+        // Create child iframe with an embedded frame that is cross-origin with its parent, but same-origin with the current frame.
         const childFrame = document.createElement('iframe')
-        childFrame.src = "../resources/parent-frame-with-child.sub.html"
+        childFrame.src = "../resources/parent-frame-with-cross-origin-child.sub.html"
         document.body.appendChild(childFrame)
 
         // Listen for postMessage() from grandchild frame.
@@ -33,5 +33,5 @@ promise_test(() => {
             resolve()
         })
     })
-}, "GetEntries of a ParentFrame with one LocalFrame child and one LocalFrame grandchild")
+}, "GetEntries of a parent Frame with one Same-Origin child and one Same-Origin grandchild")
 </script>
\ No newline at end of file
diff --git a/tests/wpt/web-platform-tests/performance-timeline/tentative/include-frames-one-local-child.html b/tests/wpt/web-platform-tests/performance-timeline/tentative/include-frames-one-same-origin-child.html
similarity index 94%
rename from tests/wpt/web-platform-tests/performance-timeline/tentative/include-frames-one-local-child.html
rename to tests/wpt/web-platform-tests/performance-timeline/tentative/include-frames-one-same-origin-child.html
index 46d4079fd20..73dc417fe6e 100644
--- a/tests/wpt/web-platform-tests/performance-timeline/tentative/include-frames-one-local-child.html
+++ b/tests/wpt/web-platform-tests/performance-timeline/tentative/include-frames-one-same-origin-child.html
@@ -33,5 +33,5 @@ promise_test(() => {
             resolve()
         })
     })
-}, "GetEntries of a Parent Frame with one LocalFrame child");
+}, "GetEntries of a parent Frame with one Same-Origin child");
 </script>
\ No newline at end of file
diff --git a/tests/wpt/web-platform-tests/performance-timeline/tentative/include-frames-two-local-children.html b/tests/wpt/web-platform-tests/performance-timeline/tentative/include-frames-two-local-children.html
index d0274050dbd..01d48445221 100644
--- a/tests/wpt/web-platform-tests/performance-timeline/tentative/include-frames-two-local-children.html
+++ b/tests/wpt/web-platform-tests/performance-timeline/tentative/include-frames-two-local-children.html
@@ -52,5 +52,5 @@ promise_test(() => {
             resolve()
         }
     })
-}, "GetEntries of a Parent Frame with two LocalFrame children")
+}, "GetEntries of a parent Frame with two Same-Origin children")
 </script>
\ No newline at end of file
diff --git a/tests/wpt/web-platform-tests/performance-timeline/tentative/performance-entry-source.html b/tests/wpt/web-platform-tests/performance-timeline/tentative/performance-entry-source.html
new file mode 100644
index 00000000000..5e51ddbbe44
--- /dev/null
+++ b/tests/wpt/web-platform-tests/performance-timeline/tentative/performance-entry-source.html
@@ -0,0 +1,33 @@
+<!DOCTYPE html>
+<head>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+</body>
+<script>
+promise_test(() => {
+    return new Promise(resolve => {
+        const navigationEntries = performance.getEntriesByType("navigation")
+        const parentEntry = navigationEntries[0]
+
+        // Parent NavigationTiming source is current window.
+        assert_equals(parentEntry.source, window)
+
+        // Create child iframe.
+        const childFrame = document.createElement('iframe')
+        childFrame.src = "../resources/child-frame.html"
+        document.body.appendChild(childFrame)
+
+        childFrame.addEventListener('load', () => {
+            const markedEntries = performance.getEntriesByName("entry-name", undefined, true)
+            const childEntry = markedEntries[0]
+
+            // Child PerformanceMark source is the child's Window.
+            assert_equals(childEntry.source, childFrame.contentWindow)
+
+            resolve()
+        })
+    })
+}, "PerformanceEntry source is equal to its respective Window")
+</script>
\ No newline at end of file
diff --git a/tests/wpt/web-platform-tests/pointerevents/pointerevent_pointercapture_in_frame.html b/tests/wpt/web-platform-tests/pointerevents/pointerevent_pointercapture_in_frame.html
index c4332ac459f..9edacd7d234 100644
--- a/tests/wpt/web-platform-tests/pointerevents/pointerevent_pointercapture_in_frame.html
+++ b/tests/wpt/web-platform-tests/pointerevents/pointerevent_pointercapture_in_frame.html
@@ -233,9 +233,14 @@ function run() {
                              .pointerMove(50, 50)
                              .pointerDown()
                              .pointerMove(200, 200)
+                             // Pause here to make sure that the previous and following pointer moves
+                             // are not coalesced. If they are coalesced, we will not see the second
+                             // move event which is when the pending lostpointercapture should be fired
+                             // (Since the pointerup event is targeted at a different frame, it won't dispatch
+                             // the pending lostpointercapture event).
+                             .pause(300)
                              .pointerMove(250, 250)
                              .pointerUp()
-                             .pointerMove(251, 251)
                              .send();
         // Wait for pointerup to fire.
         await watcher_promise;
diff --git a/tests/wpt/web-platform-tests/preload/prefetch-accept.html b/tests/wpt/web-platform-tests/preload/prefetch-accept.html
new file mode 100644
index 00000000000..3820b9b4db0
--- /dev/null
+++ b/tests/wpt/web-platform-tests/preload/prefetch-accept.html
@@ -0,0 +1,26 @@
+<!DOCTYPE html>
+<title>Ensures that prefetch works with documents</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/utils.js"></script>
+<script src="/common/dispatcher/dispatcher.js"></script>
+<script src="resources/prefetch-helper.js"></script>
+<body>
+<script>
+
+promise_test(async t => {
+    const {href, uid} = await prefetch({
+        file: "prefetch-exec.html",
+        type: "text/html",
+        origin: document.origin});
+    const popup = window.open(href + "&cache_bust=" + token());
+    const remoteContext = new RemoteContext(uid);
+    t.add_cleanup(() => popup.close());
+    await remoteContext.execute_script(() => "OK");
+    const results = await get_prefetch_info(href);
+    assert_equals(results.length, 2);
+    assert_equals(results[0].headers.accept, results[1].headers.accept);
+}, "Document prefetch should send the exact Accept header as navigation")
+
+</script>
+</body>
diff --git a/tests/wpt/web-platform-tests/preload/resources/prefetch-exec.html b/tests/wpt/web-platform-tests/preload/resources/prefetch-exec.html
new file mode 100644
index 00000000000..1d6765bc93e
--- /dev/null
+++ b/tests/wpt/web-platform-tests/preload/resources/prefetch-exec.html
@@ -0,0 +1,9 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Message BC</title>
+<script src="/common/dispatcher/dispatcher.js"></script>
+<script>
+"use strict";
+const params = new URLSearchParams(location.search);
+window.executor = new Executor(params.get("key"));
+</script>
diff --git a/tests/wpt/web-platform-tests/preload/resources/prefetch-helper.js b/tests/wpt/web-platform-tests/preload/resources/prefetch-helper.js
new file mode 100644
index 00000000000..cf0e0d583cd
--- /dev/null
+++ b/tests/wpt/web-platform-tests/preload/resources/prefetch-helper.js
@@ -0,0 +1,21 @@
+async function get_prefetch_info(href) {
+    const response = await fetch(`${href}&mode=info`, {mode: "cors"});
+    return await response.json();
+}
+
+async function prefetch(p = {}, t) {
+    const link = document.createElement("link");
+    link.rel = "prefetch";
+    if (p.crossOrigin)
+        link.setAttribute("crossorigin", p.crossOrigin);
+    const uid = token();
+    const params = new URLSearchParams();
+    params.set("key", uid);
+    for (const key in p)
+        params.set(key, p[key]);
+    const origin = p.origin || '';
+    link.href = `${origin}/preload/resources/prefetch-info.py?${params.toString()}`;
+    document.head.appendChild(link);
+    while (!(await get_prefetch_info(link.href)).length) { }
+    return {href: link.href, uid};
+}
diff --git a/tests/wpt/web-platform-tests/preload/resources/prefetch-info.py b/tests/wpt/web-platform-tests/preload/resources/prefetch-info.py
new file mode 100644
index 00000000000..04d942ba05e
--- /dev/null
+++ b/tests/wpt/web-platform-tests/preload/resources/prefetch-info.py
@@ -0,0 +1,37 @@
+import os
+from wptserve.utils import isomorphic_encode
+from json import dumps, loads
+
+def main(request, response):
+    key = request.GET.first(b"key").decode("utf8")
+    mode = request.GET.first(b"mode", "content")
+    status = int(request.GET.first(b"status", b"200"))
+    stash = request.server.stash
+    cors = request.GET.first(b"cors", "true")
+    if cors == "true" or mode == b"info":
+        response.headers.set(b"Access-Control-Allow-Origin", b"*")
+
+    response.status = status
+    with stash.lock:
+        requests = loads(stash.take(key) or '[]')
+        if mode == b"info":
+            response.headers.set(b"Content-Type", "application/json")
+            json_reqs = dumps(requests)
+            response.content = json_reqs
+            stash.put(key, json_reqs)
+            return
+        else:
+            headers = {}
+            for header, value in request.headers.items():
+                headers[header.decode("utf8")] = value[0].decode("utf8")
+            path = request.url
+            requests.append({"headers": headers, "url": request.url})
+            stash.put(key, dumps(requests))
+
+    response.headers.set(b"Content-Type", request.GET.first(b"type", "text/plain"))
+    response.headers.set(b"Cache-Control", request.GET.first(b"cache-control", b"max-age: 604800"))
+    if b"file" in request.GET:
+        path = os.path.join(os.path.dirname(isomorphic_encode(__file__)), os.path.basename(request.GET.first(b"file")))
+        response.content = open(path, mode=u'rb').read()
+    else:
+        return request.GET.first(b"content", "123")
diff --git a/tests/wpt/web-platform-tests/scroll-animations/css/animation-shorthand.html b/tests/wpt/web-platform-tests/scroll-animations/css/animation-shorthand.html
index 832b3e0cb9b..60d6c766467 100644
--- a/tests/wpt/web-platform-tests/scroll-animations/css/animation-shorthand.html
+++ b/tests/wpt/web-platform-tests/scroll-animations/css/animation-shorthand.html
@@ -17,6 +17,8 @@ test_invalid_value('animation',
   '1s linear 1s 2 reverse forwards paused anim 2000');
 test_invalid_value('animation',
   '1s linear 1s 2 reverse forwards paused anim scroll()');
+test_invalid_value('animation',
+  '1s linear 1s 2 reverse forwards paused anim view()');
 test_invalid_value('animation',
   '1s linear 1s 2 reverse forwards paused anim timeline');
 
diff --git a/tests/wpt/web-platform-tests/scroll-animations/css/animation-timeline-computed.html b/tests/wpt/web-platform-tests/scroll-animations/css/animation-timeline-computed.html
index 29486a02c19..a77233aab90 100644
--- a/tests/wpt/web-platform-tests/scroll-animations/css/animation-timeline-computed.html
+++ b/tests/wpt/web-platform-tests/scroll-animations/css/animation-timeline-computed.html
@@ -58,4 +58,12 @@ test_computed_value('animation-timeline', 'scroll(root)');
 test_computed_value('animation-timeline', 'scroll(nearest)', 'scroll()');
 test_computed_value('animation-timeline', 'scroll(inline nearest)', 'scroll(inline)');
 test_computed_value('animation-timeline', 'scroll(vertical root)');
+
+// https://drafts.csswg.org/scroll-animations-1/#view-notation
+test_computed_value('animation-timeline', 'view()');
+test_computed_value('animation-timeline', 'view(block)', 'view()');
+test_computed_value('animation-timeline', 'view(inline)');
+test_computed_value('animation-timeline', 'view(horizontal)');
+test_computed_value('animation-timeline', 'view(vertical)');
+
 </script>
diff --git a/tests/wpt/web-platform-tests/scroll-animations/css/animation-timeline-parsing.html b/tests/wpt/web-platform-tests/scroll-animations/css/animation-timeline-parsing.html
index 5691026dbcc..dc22778fa7a 100644
--- a/tests/wpt/web-platform-tests/scroll-animations/css/animation-timeline-parsing.html
+++ b/tests/wpt/web-platform-tests/scroll-animations/css/animation-timeline-parsing.html
@@ -55,4 +55,16 @@ test_invalid_value('animation-timeline', 'scroll(abc root)');
 test_invalid_value('animation-timeline', 'scroll(abc)');
 test_invalid_value('animation-timeline', 'scroll(vertical abc)');
 test_invalid_value('animation-timeline', 'scroll("string")');
+
+// https://drafts.csswg.org/scroll-animations-1/#scroll-notation
+test_valid_value('animation-timeline', 'view()');
+test_valid_value('animation-timeline', 'view(block)', 'view()');
+test_valid_value('animation-timeline', 'view(inline)');
+test_valid_value('animation-timeline', 'view(horizontal)');
+test_valid_value('animation-timeline', 'view(vertical)');
+
+test_invalid_value('animation-timeline', 'view(abc block)');
+test_invalid_value('animation-timeline', 'view(abc)');
+test_invalid_value('animation-timeline', 'view(vertical abc)');
+test_invalid_value('animation-timeline', 'view("string")');
 </script>
diff --git a/tests/wpt/web-platform-tests/speculation-rules/prefetch/no-vary-search/README.txt b/tests/wpt/web-platform-tests/speculation-rules/prefetch/no-vary-search/README.txt
new file mode 100644
index 00000000000..60ac226f8cd
--- /dev/null
+++ b/tests/wpt/web-platform-tests/speculation-rules/prefetch/no-vary-search/README.txt
@@ -0,0 +1 @@
+Web Platform Tests for No-Vary-Search support in prefetch cache.
diff --git a/tests/wpt/web-platform-tests/speculation-rules/prerender/csp-script-src-elem-inline-speculation-rules.tentative.html b/tests/wpt/web-platform-tests/speculation-rules/prerender/csp-script-src-elem-inline-speculation-rules.tentative.html
new file mode 100644
index 00000000000..0a3b3b8a70a
--- /dev/null
+++ b/tests/wpt/web-platform-tests/speculation-rules/prerender/csp-script-src-elem-inline-speculation-rules.tentative.html
@@ -0,0 +1,28 @@
+<!DOCTYPE html>
+<meta name="timeout" content="long">
+<script src="/common/utils.js"></script>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="resources/utils.js"></script>
+
+<body>
+  <script>
+    setup(() => assertSpeculationRulesIsSupported());
+
+    promise_test(async t => {
+      // The key used for storing a test result in the server.
+      const key = token();
+
+      // Open the test runner in a popup - it will prerender itself, record the
+      // test results, and send them back to this harness.
+      const url =
+        `resources/csp-script-src-elem-inline-speculation-rules.html?key=${key}`;
+      window.open(url, '_blank', 'noopener');
+
+      // Wait until the test sends us the results.
+      const result = await nextValueFromServer(key);
+
+      assert_equals(result, "true", "initial document.prerendering");
+    }, 'Test if CSP script-src-elem inline-speculation-rules permits inline speculationrules.');
+  </script>
+</body>
diff --git a/tests/wpt/web-platform-tests/speculation-rules/prerender/resources/csp-script-src-elem-inline-speculation-rules.html b/tests/wpt/web-platform-tests/speculation-rules/prerender/resources/csp-script-src-elem-inline-speculation-rules.html
new file mode 100644
index 00000000000..19aff92206f
--- /dev/null
+++ b/tests/wpt/web-platform-tests/speculation-rules/prerender/resources/csp-script-src-elem-inline-speculation-rules.html
@@ -0,0 +1,14 @@
+<!DOCTYPE html>
+
+<head>
+  <meta http-equiv="Content-Security-Policy" content="script-src-elem 'self' 'inline-speculation-rules'">
+</head>
+<script src="/common/utils.js"></script>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="utils.js"></script>
+<script src="csp-script-src.js"></script>
+<script>
+  const params = new URLSearchParams(location.search);
+  writeValueToServer(params.get('key'), "csp is ignored unexpectedly");
+</script>
diff --git a/tests/wpt/web-platform-tests/speculation-rules/prerender/resources/notification-on-activation.html b/tests/wpt/web-platform-tests/speculation-rules/prerender/resources/notification-on-activation.html
index 03e36f06c13..0a85746b041 100644
--- a/tests/wpt/web-platform-tests/speculation-rules/prerender/resources/notification-on-activation.html
+++ b/tests/wpt/web-platform-tests/speculation-rules/prerender/resources/notification-on-activation.html
@@ -26,6 +26,7 @@ if (!isPrerendering) {
   document.addEventListener('prerenderingchange', () => {
     // Accessing the Notification API is allowed after the prerendering state
     // changed.
+    const permission = Notification.permission;
     const notification = new Notification('New Notification');
 
     notification.onerror = function(_) {
diff --git a/tests/wpt/web-platform-tests/trust-tokens/end-to-end/README.txt b/tests/wpt/web-platform-tests/trust-tokens/end-to-end/README.txt
index a86468df9d6..82d3cc844bd 100644
--- a/tests/wpt/web-platform-tests/trust-tokens/end-to-end/README.txt
+++ b/tests/wpt/web-platform-tests/trust-tokens/end-to-end/README.txt
@@ -1,4 +1,5 @@
-These tests confirm that Trust Tokens protocol operations executed correctly end
-to end (in contrast to just checking, as the parent directory's
-trust-token-parameter-validation does, that a method's interface is present and
-correctly rejects invalid arguments).
+These tests confirm that Private State Tokens protocol operations
+executed correctly end to end (in contrast to just checking, as the
+parent directory's trust-token-parameter-validation does, that a
+method's interface is present and correctly rejects invalid
+arguments).
diff --git a/tests/wpt/web-platform-tests/trust-tokens/end-to-end/has-trust-token-with-no-top-frame.tentative.https.html b/tests/wpt/web-platform-tests/trust-tokens/end-to-end/has-trust-token-with-no-top-frame.tentative.https.html
index 38ebed9119a..587c641d8dc 100644
--- a/tests/wpt/web-platform-tests/trust-tokens/end-to-end/has-trust-token-with-no-top-frame.tentative.https.html
+++ b/tests/wpt/web-platform-tests/trust-tokens/end-to-end/has-trust-token-with-no-top-frame.tentative.https.html
@@ -1,6 +1,6 @@
 <!DOCTYPE html>
 <meta charset="utf-8">
-<title>Tests the Private State Token API's hasPrivateStateToken behavior in documents with no top frame</title>
+<title>Tests the Private Token API's hasPrivateToken behavior in documents with no top frame</title>
 <link rel="help" href="https://github.com/WICG/trust-token-api" />
 <script src="/resources/testharness.js"></script>
 <script src="/resources/testharnessreport.js"></script>
@@ -15,8 +15,8 @@
     frame.remove();
 
     test(() => {
-      assert_equals(cachedDocument.hasPrivateStateToken("https://issuer.example"), undefined,
+      assert_equals(cachedDocument.hasPrivateToken("https://issuer.example", 'private-state-token'), undefined,
         "Can't construct a Promise in a destroyed execution context.");
-    }, 'hasPrivateStateToken in a destroyed document.');
+    }, 'hasPrivateToken in a destroyed document.');
   </script>
 </body>
diff --git a/tests/wpt/web-platform-tests/web-animations/responsive/columnGap.html b/tests/wpt/web-platform-tests/web-animations/responsive/columnGap.html
index fa85272d49d..43d44152cb5 100644
--- a/tests/wpt/web-platform-tests/web-animations/responsive/columnGap.html
+++ b/tests/wpt/web-platform-tests/web-animations/responsive/columnGap.html
@@ -26,11 +26,11 @@ test(function() {
 
     player.currentTime = 5;
     element.style.fontSize = '40px';
-    assert_equals(getComputedStyle(element).columnGap, '0px');
+    assert_equals(getComputedStyle(element).columnGap, '20px');
 
     player.currentTime = 7.5;
-    assert_equals(getComputedStyle(element).columnGap, '0px');
-}, 'column-gap clamped to 0px');
+    assert_equals(getComputedStyle(element).columnGap, '10px');
+}, 'column-gap clamped to 0px on keyframes');
 
 test(function() {
     container.style.columnGap = 'normal';
diff --git a/tests/wpt/web-platform-tests/web-animations/responsive/lineHeight.html b/tests/wpt/web-platform-tests/web-animations/responsive/lineHeight.html
index 16c12a7456a..03d45e54c16 100644
--- a/tests/wpt/web-platform-tests/web-animations/responsive/lineHeight.html
+++ b/tests/wpt/web-platform-tests/web-animations/responsive/lineHeight.html
@@ -26,11 +26,11 @@ test(function() {
 
     player.currentTime = 5;
     element.style.fontSize = '40px';
-    assert_equals(getComputedStyle(element).lineHeight, '0px');
+    assert_equals(getComputedStyle(element).lineHeight, '20px');
 
     player.currentTime = 7.5;
-    assert_equals(getComputedStyle(element).lineHeight, '0px');
-}, 'lineHeight clamped to 0px');
+    assert_equals(getComputedStyle(element).lineHeight, '10px');
+}, 'lineHeight clamped to 0px on keyframes');
 
 test(function() {
     container.style.lineHeight = 'normal';
diff --git a/tests/wpt/web-platform-tests/web-animations/responsive/minHeight.html b/tests/wpt/web-platform-tests/web-animations/responsive/minHeight.html
index 7055b53f147..07474bc3f44 100644
--- a/tests/wpt/web-platform-tests/web-animations/responsive/minHeight.html
+++ b/tests/wpt/web-platform-tests/web-animations/responsive/minHeight.html
@@ -21,11 +21,15 @@ test(function() {
 
 test(function() {
     element.style.fontSize = '10px';
-    var player = element.animate([{minHeight: '30px'}, {minHeight: 'calc(30px - 2em)'}], 10);
+    var player = element.animate([{minHeight: '40px'}, {minHeight: 'calc(40px - 2em)'}], 10);
     player.pause();
-    player.currentTime = 7.5;
+
+    player.currentTime = 5;
     element.style.fontSize = '40px';
-    assert_equals(getComputedStyle(element).minHeight, '0px');
-}, 'minHeight clamped to 0px');
+    assert_equals(getComputedStyle(element).minHeight, '20px');
+
+    player.currentTime = 7.5;
+    assert_equals(getComputedStyle(element).minHeight, '10px');
+}, 'minHeight clamped to 0px on keyframes');
 
 </script>
diff --git a/tests/wpt/web-platform-tests/web-animations/responsive/perspective.html b/tests/wpt/web-platform-tests/web-animations/responsive/perspective.html
index 2c2852639aa..f32b4dbad32 100644
--- a/tests/wpt/web-platform-tests/web-animations/responsive/perspective.html
+++ b/tests/wpt/web-platform-tests/web-animations/responsive/perspective.html
@@ -26,11 +26,11 @@ test(function() {
 
     player.currentTime = 5;
     element.style.fontSize = '40px';
-    assert_equals(getComputedStyle(element).perspective, '0px');
+    assert_equals(getComputedStyle(element).perspective, '20px');
 
     player.currentTime = 7.5;
-    assert_equals(getComputedStyle(element).perspective, '0px');
-}, 'perspective clamped to 0px');
+    assert_equals(getComputedStyle(element).perspective, '10px');
+}, 'perspective clamped to 0px on keyframes');
 
 test(function() {
     container.style.perspective = 'none';
diff --git a/tests/wpt/web-platform-tests/web-animations/responsive/rowGap.html b/tests/wpt/web-platform-tests/web-animations/responsive/rowGap.html
index ad184610ce2..b7dae62f238 100644
--- a/tests/wpt/web-platform-tests/web-animations/responsive/rowGap.html
+++ b/tests/wpt/web-platform-tests/web-animations/responsive/rowGap.html
@@ -26,11 +26,11 @@ test(function() {
 
     player.currentTime = 5;
     element.style.fontSize = '40px';
-    assert_equals(getComputedStyle(element).rowGap, '0px');
+    assert_equals(getComputedStyle(element).rowGap, '20px');
 
     player.currentTime = 7.5;
-    assert_equals(getComputedStyle(element).rowGap, '0px');
-}, 'row-gap clamped to 0px');
+    assert_equals(getComputedStyle(element).rowGap, '10px');
+}, 'row-gap clamped to 0px on keyframes');
 
 test(function() {
     container.style.rowGap = 'normal';
diff --git a/tests/wpt/web-platform-tests/webcodecs/reconfiguring-encoder.https.any.js b/tests/wpt/web-platform-tests/webcodecs/reconfiguring-encoder.https.any.js
index c380fa772ff..7bc7402b011 100644
--- a/tests/wpt/web-platform-tests/webcodecs/reconfiguring-encoder.https.any.js
+++ b/tests/wpt/web-platform-tests/webcodecs/reconfiguring-encoder.https.any.js
@@ -89,6 +89,7 @@ promise_test(async t => {
   for (let i = 0; i < frames_to_encode; i++) {
     var frame = createFrame(original_w, original_h, next_ts++);
     encoder.encode(frame, {});
+    frame.close();
   }
 
   params.width = new_w;
@@ -102,6 +103,7 @@ promise_test(async t => {
   for (let i = 0; i < frames_to_encode; i++) {
     var frame = createFrame(new_w, new_h, next_ts++);
     encoder.encode(frame, {});
+    frame.close();
   }
 
   await encoder.flush();
diff --git a/tests/wpt/web-platform-tests/webcodecs/video-encoder-utils.js b/tests/wpt/web-platform-tests/webcodecs/video-encoder-utils.js
index fad6b909505..7201e054d81 100644
--- a/tests/wpt/web-platform-tests/webcodecs/video-encoder-utils.js
+++ b/tests/wpt/web-platform-tests/webcodecs/video-encoder-utils.js
@@ -6,12 +6,6 @@ async function checkEncoderSupport(test, config) {
     supported = support.supported;
   } catch (e) {}
 
-  if (!supported) {
-    // Mark the test 'passed', unfortunately assert_implements_optional()
-    // doesn't do it by itself.
-    test.done();
-  }
-
   assert_implements_optional(supported, 'Unsupported config: ' +
                              JSON.stringify(config));
 }
diff --git a/tests/wpt/web-platform-tests/webcodecs/video-encoder.https.any.js b/tests/wpt/web-platform-tests/webcodecs/video-encoder.https.any.js
index 063be1ef0fd..b5c511d4062 100644
--- a/tests/wpt/web-platform-tests/webcodecs/video-encoder.https.any.js
+++ b/tests/wpt/web-platform-tests/webcodecs/video-encoder.https.any.js
@@ -63,6 +63,10 @@ promise_test(async t => {
 
   let frame1 = createFrame(640, 480, 0);
   let frame2 = createFrame(640, 480, 33333);
+  t.add_cleanup(() => {
+    frame1.close();
+    frame2.close();
+  });
 
   encoder.encode(frame1);
   encoder.encode(frame2);
diff --git a/tests/wpt/web-platform-tests/webdriver/tests/bidi/browsing_context/classic_interop/__init__.py b/tests/wpt/web-platform-tests/webdriver/tests/bidi/browsing_context/classic_interop/__init__.py
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/tests/wpt/web-platform-tests/webdriver/tests/bidi/browsing_context/classic_interop/window_handle.py b/tests/wpt/web-platform-tests/webdriver/tests/bidi/browsing_context/classic_interop/window_handle.py
new file mode 100644
index 00000000000..4f36fba1973
--- /dev/null
+++ b/tests/wpt/web-platform-tests/webdriver/tests/bidi/browsing_context/classic_interop/window_handle.py
@@ -0,0 +1,7 @@
+import pytest
+
+pytestmark = pytest.mark.asyncio
+
+
+async def test_top_level_context_id_equals_window_handle(top_context, current_session):
+    assert top_context["context"] == current_session.window_handle
diff --git a/tests/wpt/web-platform-tests/webrtc-extensions/RTCRtpParameters-maxFramerate.html b/tests/wpt/web-platform-tests/webrtc-extensions/RTCRtpParameters-maxFramerate.html
index c1d47238600..3e348f0d147 100644
--- a/tests/wpt/web-platform-tests/webrtc-extensions/RTCRtpParameters-maxFramerate.html
+++ b/tests/wpt/web-platform-tests/webrtc-extensions/RTCRtpParameters-maxFramerate.html
@@ -8,7 +8,7 @@
 <script>
 'use strict';
 
-test(function(t) {
+test(t => {
   const pc = new RTCPeerConnection();
   t.add_cleanup(() => pc.close());
   assert_throws_js(RangeError, () => pc.addTransceiver('video', {
@@ -18,6 +18,54 @@ test(function(t) {
   }));
 }, `addTransceiver() with sendEncoding.maxFramerate field set to less than 0 should reject with RangeError`);
 
+test(t => {
+  const pc = new RTCPeerConnection();
+  t.add_cleanup(() => pc.close());
+  let {sender} = pc.addTransceiver('audio', {
+    sendEncodings: [{
+      maxFramerate: -10
+    }]
+  });
+  let encodings = sender.getParameters().encodings;
+  assert_equals(encodings.length, 1);
+  assert_not_own_property(encodings[0], "maxFramerate");
+
+  sender = pc.addTransceiver('audio', {
+    sendEncodings: [{
+      maxFramerate: 10
+    }]
+  }).sender;
+  encodings = sender.getParameters().encodings;
+  assert_equals(encodings.length, 1);
+  assert_not_own_property(encodings[0], "maxFramerate");
+}, `addTransceiver('audio') with sendEncoding.maxFramerate should succeed, but remove the maxFramerate, even if it is invalid`);
+
+promise_test(async t => {
+  const pc = new RTCPeerConnection();
+  t.add_cleanup(() => pc.close());
+  const {sender} = pc.addTransceiver('audio');
+  let params = sender.getParameters();
+  assert_equals(params.encodings.length, 1);
+  params.encodings[0].maxFramerate = 20;
+  await sender.setParameters(params);
+  const {encodings} = sender.getParameters();
+  assert_equals(encodings.length, 1);
+  assert_not_own_property(encodings[0], "maxFramerate");
+}, `setParameters with maxFramerate on an audio sender should succeed, but remove the maxFramerate`);
+
+promise_test(async t => {
+  const pc = new RTCPeerConnection();
+  t.add_cleanup(() => pc.close());
+  const {sender} = pc.addTransceiver('audio');
+  let params = sender.getParameters();
+  assert_equals(params.encodings.length, 1);
+  params.encodings[0].maxFramerate = -1;
+  await sender.setParameters(params);
+  const {encodings} = sender.getParameters();
+  assert_equals(encodings.length, 1);
+  assert_not_own_property(encodings[0], "maxFramerate");
+}, `setParameters with an invalid maxFramerate on an audio sender should succeed, but remove the maxFramerate`);
+
 promise_test(async t => {
   const pc = new RTCPeerConnection();
   t.add_cleanup(() => pc.close());
@@ -25,15 +73,29 @@ promise_test(async t => {
   await doOfferAnswerExchange(t, pc);
 
   const param = sender.getParameters();
-  validateSenderRtpParameters(param);
-  const encoding = getFirstEncoding(param);
+  const encoding = param.encodings[0];
+  assert_not_own_property(encoding, "maxFramerate");
 
   encoding.maxFramerate = -10;
   return promise_rejects_js(t, RangeError,
     sender.setParameters(param));
 }, `setParameters() with encoding.maxFramerate field set to less than 0 should reject with RangeError`);
 
+// It would be great if we could test to see whether maxFramerate is actually
+// honored.
 test_modified_encoding('video', 'maxFramerate', 24, 16,
-  'setParameters() with modified encoding.maxFramerate should succeed');
+  'setParameters() with maxFramerate 24->16 should succeed');
+
+test_modified_encoding('video', 'maxFramerate', undefined, 16,
+  'setParameters() with maxFramerate undefined->16 should succeed');
+
+test_modified_encoding('video', 'maxFramerate', 24, undefined,
+  'setParameters() with maxFramerate 24->undefined should succeed');
+
+test_modified_encoding('video', 'maxFramerate', 0, 16,
+  'setParameters() with maxFramerate 0->16 should succeed');
+
+test_modified_encoding('video', 'maxFramerate', 24, 0,
+  'setParameters() with maxFramerate 24->0 should succeed');
 
 </script>
diff --git a/tests/wpt/web-platform-tests/webrtc/RTCPeerConnection-addTransceiver.https.html b/tests/wpt/web-platform-tests/webrtc/RTCPeerConnection-addTransceiver.https.html
index 68a2623391b..3fd83a76fe2 100644
--- a/tests/wpt/web-platform-tests/webrtc/RTCPeerConnection-addTransceiver.https.html
+++ b/tests/wpt/web-platform-tests/webrtc/RTCPeerConnection-addTransceiver.https.html
@@ -325,7 +325,7 @@
     assert_idl_attribute(pc, 'addTransceiver');
 
     assert_throws_js(TypeError, () =>
-      pc.addTransceiver('audio', {
+      pc.addTransceiver('video', {
         sendEncodings: [{
           rid: '@Invalid!'
         }]
@@ -359,7 +359,7 @@
     const pc = new RTCPeerConnection();
     t.add_cleanup(() => pc.close());
 
-    pc.addTransceiver('audio', {
+    pc.addTransceiver('video', {
       sendEncodings: [{
         dtx: 'enabled',
         active: false,
diff --git a/tests/wpt/web-platform-tests/webrtc/RTCRtpParameters-encodings.html b/tests/wpt/web-platform-tests/webrtc/RTCRtpParameters-encodings.html
index e1a6e625379..b68347cbaf9 100644
--- a/tests/wpt/web-platform-tests/webrtc/RTCRtpParameters-encodings.html
+++ b/tests/wpt/web-platform-tests/webrtc/RTCRtpParameters-encodings.html
@@ -12,7 +12,6 @@
   // https://w3c.github.io/webrtc-pc/archives/20170605/webrtc.html
 
   // The following helper functions are called from RTCRtpParameters-helper.js:
-  //   doOfferAnswerExchange
   //   validateSenderRtpParameters
 
   /*
@@ -57,6 +56,19 @@
         - encodings is set to the value of the [[send encodings]] internal slot.
    */
 
+  promise_test(async t => {
+    const pc = new RTCPeerConnection();
+    t.add_cleanup(() => pc.close());
+    const transceiver = pc.addTransceiver('video');
+
+    const param = transceiver.sender.getParameters();
+    assert_equals(param.encodings.length, 1);
+    // Do not call this in every test; it does not make sense to disable all of
+    // the tests below for an implementation that is missing support for
+    // fields that are not related to the test.
+    validateSenderRtpParameters(param);
+  }, `getParameters should return RTCRtpEncodingParameters with all required fields`);
+
   /*
     5.1.  addTransceiver
       7. Create an RTCRtpSender with track, streams and sendEncodings and let sender
@@ -75,29 +87,229 @@
     const pc = new RTCPeerConnection();
     t.add_cleanup(() => pc.close());
     const transceiver = pc.addTransceiver('audio');
-    await doOfferAnswerExchange(t, pc);
 
     const param = transceiver.sender.getParameters();
-    validateSenderRtpParameters(param);
     const { encodings } = param;
-    const encoding = getFirstEncoding(param);
+    assert_equals(encodings.length, 1);
+    const encoding = param.encodings[0];
 
     assert_equals(encoding.active, true);
-  }, 'addTransceiver() with undefined sendEncodings should have default encoding parameter with active set to true');
+    assert_not_own_property(encoding, "maxBitrate");
+    assert_not_own_property(encoding, "rid");
+    assert_not_own_property(encoding, "scaleResolutionDownBy");
+    // We do not check props from extension specifications here; those checks
+    // need to go in a test-case for that extension specification.
+  }, 'addTransceiver(audio) with undefined sendEncodings should have default encoding parameter with active set to true');
+
+  promise_test(async t => {
+    const pc = new RTCPeerConnection();
+    t.add_cleanup(() => pc.close());
+    const transceiver = pc.addTransceiver('video');
+
+    const param = transceiver.sender.getParameters();
+    const { encodings } = param;
+    assert_equals(encodings.length, 1);
+    const encoding = param.encodings[0];
+
+    assert_equals(encoding.active, true);
+    // spec says to return an encoding without a scaleResolutionDownBy value
+    // when addTransceiver does not pass any encodings, however spec also says
+    // to throw if setParameters is missing a scaleResolutionDownBy. One of
+    // these two requirements needs to be removed, but it is unclear right now
+    // which will be removed. For now, allow scaleResolutionDownBy, but don't
+    // require it.
+    // https://github.com/w3c/webrtc-pc/issues/2730
+    assert_not_own_property(encoding, "maxBitrate");
+    assert_not_own_property(encoding, "rid");
+    assert_equals(encoding.scaleResolutionDownBy, 1.0);
+    // We do not check props from extension specifications here; those checks
+    // need to go in a test-case for that extension specification.
+  }, 'addTransceiver(video) with undefined sendEncodings should have default encoding parameter with active set to true and scaleResolutionDownBy set to 1');
 
   promise_test(async t => {
     const pc = new RTCPeerConnection();
     t.add_cleanup(() => pc.close());
     const transceiver = pc.addTransceiver('audio', { sendEncodings: [] });
-    await doOfferAnswerExchange(t, pc);
 
     const param = transceiver.sender.getParameters();
-    validateSenderRtpParameters(param);
     const { encodings } = param;
-    const encoding = getFirstEncoding(param);
+    assert_equals(encodings.length, 1);
+    const encoding = param.encodings[0];
 
     assert_equals(encoding.active, true);
-  }, 'addTransceiver() with empty list sendEncodings should have default encoding parameter with active set to true');
+    assert_not_own_property(encoding, "maxBitrate");
+    assert_not_own_property(encoding, "rid");
+    assert_not_own_property(encoding, "scaleResolutionDownBy");
+    // We do not check props from extension specifications here; those checks
+    // need to go in a test-case for that extension specification.
+  }, 'addTransceiver(audio) with empty list sendEncodings should have default encoding parameter with active set to true');
+
+  promise_test(async t => {
+    const pc = new RTCPeerConnection();
+    t.add_cleanup(() => pc.close());
+    const transceiver = pc.addTransceiver('video', { sendEncodings: [] });
+
+    const param = transceiver.sender.getParameters();
+    const { encodings } = param;
+    assert_equals(encodings.length, 1);
+    const encoding = param.encodings[0];
+
+    assert_equals(encoding.active, true);
+    assert_not_own_property(encoding, "maxBitrate");
+    assert_not_own_property(encoding, "rid");
+    assert_equals(encoding.scaleResolutionDownBy, 1.0);
+    // We do not check props from extension specifications here; those checks
+    // need to go in a test-case for that extension specification.
+  }, 'addTransceiver(video) with empty list sendEncodings should have default encoding parameter with active set to true and scaleResolutionDownBy set to 1');
+
+  promise_test(async t => {
+    const pc = new RTCPeerConnection();
+    t.add_cleanup(() => pc.close());
+    const transceiver = pc.addTransceiver('video', {sendEncodings: [{rid: "foo"}, {rid: "bar", scaleResolutionDownBy: 3.0}]});
+
+    const param = transceiver.sender.getParameters();
+    const { encodings } = param;
+    assert_equals(encodings.length, 2);
+    assert_equals(encodings[0].scaleResolutionDownBy, 1.0);
+    assert_equals(encodings[1].scaleResolutionDownBy, 3.0);
+  }, `addTransceiver(video) should auto-set scaleResolutionDownBy to 1 when some encodings have it, but not all`);
+
+  promise_test(async t => {
+    const pc = new RTCPeerConnection();
+    t.add_cleanup(() => pc.close());
+    const transceiver = pc.addTransceiver('video', {sendEncodings: [{rid: "foo"}, {rid: "bar"}]});
+
+    const param = transceiver.sender.getParameters();
+    const { encodings } = param;
+    assert_equals(encodings.length, 2);
+    assert_equals(encodings[0].scaleResolutionDownBy, 2.0);
+    assert_equals(encodings[1].scaleResolutionDownBy, 1.0);
+  }, `addTransceiver should auto-set scaleResolutionDownBy to powers of 2 (descending) when absent`);
+
+  promise_test(async t => {
+    const pc = new RTCPeerConnection();
+    t.add_cleanup(() => pc.close());
+    const sendEncodings = [];
+    for (let i = 0; i < 1000; i++) {
+      sendEncodings.push({rid: i});
+    }
+    const transceiver = pc.addTransceiver('video', {sendEncodings});
+
+    const param = transceiver.sender.getParameters();
+    const { encodings } = param;
+    assert_less_than(encodings.length, 1000, `1000 encodings is clearly too many`);
+  }, `addTransceiver with a ridiculous number of encodings should truncate the list`);
+
+  promise_test(async t => {
+    const pc = new RTCPeerConnection();
+    t.add_cleanup(() => pc.close());
+    const transceiver = pc.addTransceiver('audio', {sendEncodings: [{rid: "foo"}, {rid: "bar"}]});
+
+    const param = transceiver.sender.getParameters();
+    const { encodings } = param;
+    assert_equals(encodings.length, 1);
+    assert_not_own_property(encodings[0], "maxBitrate");
+    assert_not_own_property(encodings[0], "rid");
+    assert_not_own_property(encodings[0], "scaleResolutionDownBy");
+    // We do not check props from extension specifications here; those checks
+    // need to go in a test-case for that extension specification.
+  }, `addTransceiver(audio) with multiple encodings should result in one encoding with no properties other than active`);
+
+  promise_test(async t => {
+    const pc = new RTCPeerConnection();
+    t.add_cleanup(() => pc.close());
+    const {sender} = pc.addTransceiver('audio', {sendEncodings: [{rid: "foo", scaleResolutionDownBy: 2.0}]});
+    const {encodings} = sender.getParameters();
+    assert_equals(encodings.length, 1);
+    assert_not_own_property(encodings[0], "scaleResolutionDownBy");
+  }, `addTransceiver(audio) should remove valid scaleResolutionDownBy`);
+
+  promise_test(async t => {
+    const pc = new RTCPeerConnection();
+    t.add_cleanup(() => pc.close());
+    const {sender} = pc.addTransceiver('audio', {sendEncodings: [{rid: "foo", scaleResolutionDownBy: -1.0}]});
+    const {encodings} = sender.getParameters();
+    assert_equals(encodings.length, 1);
+    assert_not_own_property(encodings[0], "scaleResolutionDownBy");
+  }, `addTransceiver(audio) should remove invalid scaleResolutionDownBy`);
+
+  promise_test(async t => {
+    const pc = new RTCPeerConnection();
+    t.add_cleanup(() => pc.close());
+    const {sender} = pc.addTransceiver('audio');
+    let params = sender.getParameters();
+    assert_equals(params.encodings.length, 1);
+    params.encodings[0].scaleResolutionDownBy = 2;
+    await sender.setParameters(params);
+    const {encodings} = sender.getParameters();
+    assert_equals(encodings.length, 1);
+    assert_not_own_property(encodings[0], "scaleResolutionDownBy");
+  }, `setParameters with scaleResolutionDownBy on an audio sender should succeed, but remove the scaleResolutionDownBy`);
+
+  promise_test(async t => {
+    const pc = new RTCPeerConnection();
+    t.add_cleanup(() => pc.close());
+    const {sender} = pc.addTransceiver('audio');
+    let params = sender.getParameters();
+    assert_equals(params.encodings.length, 1);
+    params.encodings[0].scaleResolutionDownBy = -1;
+    await sender.setParameters(params);
+    const {encodings} = sender.getParameters();
+    assert_equals(encodings.length, 1);
+    assert_not_own_property(encodings[0], "scaleResolutionDownBy");
+  }, `setParameters with an invalid scaleResolutionDownBy on an audio sender should succeed, but remove the scaleResolutionDownBy`);
+
+  promise_test(async t => {
+    const pc = new RTCPeerConnection();
+    t.add_cleanup(() => pc.close());
+
+    assert_throws_js(TypeError, () => pc.addTransceiver('video', { sendEncodings: [{rid: "foo"}, {rid: "foo"}] }));
+  }, 'addTransceiver with duplicate rid and multiple encodings throws TypeError');
+
+  promise_test(async t => {
+    const pc = new RTCPeerConnection();
+    t.add_cleanup(() => pc.close());
+
+    assert_throws_js(TypeError, () => pc.addTransceiver('video', { sendEncodings: [{rid: "foo"}, {}] }));
+  }, 'addTransceiver with missing rid and multiple encodings throws TypeError');
+
+  promise_test(async t => {
+    const pc = new RTCPeerConnection();
+    t.add_cleanup(() => pc.close());
+
+    assert_throws_js(TypeError, () => pc.addTransceiver('video', { sendEncodings: [{rid: ""}] }));
+  }, 'addTransceiver with empty rid throws TypeError');
+
+  promise_test(async t => {
+    const pc = new RTCPeerConnection();
+    t.add_cleanup(() => pc.close());
+
+    assert_throws_js(TypeError, () => pc.addTransceiver('video', { sendEncodings: [{rid: "!?"}] }));
+    assert_throws_js(TypeError, () => pc.addTransceiver('video', { sendEncodings: [{rid: "(╯°□°)╯︵ ┻━┻"}] }));
+    // RFC 8851 says '-' and '_' are allowed, but RFC 8852 says they are not.
+    // RFC 8852 needs to be adhered to, otherwise we can't put the rid in RTP
+    // https://github.com/w3c/webrtc-pc/issues/2732
+    // https://www.rfc-editor.org/errata/eid7132
+    assert_throws_js(TypeError, () => pc.addTransceiver('video', { sendEncodings: [{rid: "foo-bar"}] }));
+    assert_throws_js(TypeError, () => pc.addTransceiver('video', { sendEncodings: [{rid: "foo_bar"}] }));
+  }, 'addTransceiver with invalid rid characters throws TypeError');
+
+  promise_test(async t => {
+    const pc = new RTCPeerConnection();
+    t.add_cleanup(() => pc.close());
+
+    // https://github.com/w3c/webrtc-pc/issues/2732
+    assert_throws_js(TypeError, () => pc.addTransceiver('video', { sendEncodings: [{rid: 'a'.repeat(256)}] }));
+  }, 'addTransceiver with rid longer than 255 characters throws TypeError');
+
+  promise_test(async t => {
+    const pc = new RTCPeerConnection();
+    t.add_cleanup(() => pc.close());
+
+    assert_throws_js(RangeError, () => pc.addTransceiver('video', { sendEncodings: [{scaleResolutionDownBy: -1}] }));
+    assert_throws_js(RangeError, () => pc.addTransceiver('video', { sendEncodings: [{scaleResolutionDownBy: 0}] }));
+    assert_throws_js(RangeError, () => pc.addTransceiver('video', { sendEncodings: [{scaleResolutionDownBy: 0.5}] }));
+  }, `addTransceiver with scaleResolutionDownBy < 1 throws RangeError`);
 
   /*
     5.2.  create an RTCRtpSender
@@ -123,11 +335,9 @@
         rid: 'foo'
       }]
     });
-    await doOfferAnswerExchange(t, pc);
 
     const param = sender.getParameters();
-    validateSenderRtpParameters(param);
-    const encoding = getFirstEncoding(param);
+    const encoding = param.encodings[0];
 
     assert_equals(encoding.active, false);
     assert_equals(encoding.maxBitrate, 8);
@@ -149,33 +359,64 @@
   promise_test(async t => {
     const pc = new RTCPeerConnection();
     t.add_cleanup(() => pc.close());
-    const { sender } = pc.addTransceiver('audio');
-    await doOfferAnswerExchange(t, pc);
+    const { sender } = pc.addTransceiver('video');
 
     const param = sender.getParameters();
-    validateSenderRtpParameters(param);
 
     const { encodings } = param;
     assert_equals(encodings.length, 1);
 
-    // {} is valid RTCRtpEncodingParameters because all fields are optional
-    encodings.push({});
+    // While {} is valid RTCRtpEncodingParameters because all fields are
+    // optional, it is still invalid to be missing a rid when there are multiple
+    // encodings. Only trigger one kind of error here.
+    encodings.push({ rid: "foo" });
     assert_equals(param.encodings.length, 2);
 
     return promise_rejects_dom(t, 'InvalidModificationError',
       sender.setParameters(param));
-  }, `sender.setParameters() with mismatch number of encodings should reject with InvalidModificationError`);
+  }, `sender.setParameters() with added encodings should reject with InvalidModificationError`);
 
   promise_test(async t => {
     const pc = new RTCPeerConnection();
     t.add_cleanup(() => pc.close());
-    const { sender } = pc.addTransceiver('audio');
-    await doOfferAnswerExchange(t, pc);
+    const { sender } = pc.addTransceiver('video', {sendEncodings: [{rid: "foo"}, {rid: "bar"}]});
 
     const param = sender.getParameters();
-    validateSenderRtpParameters(param);
 
-    param.encodings = undefined;
+    const { encodings } = param;
+    assert_equals(encodings.length, 2);
+
+    encodings.pop();
+    assert_equals(param.encodings.length, 1);
+
+    return promise_rejects_dom(t, 'InvalidModificationError',
+      sender.setParameters(param));
+  }, `sender.setParameters() with removed encodings should reject with InvalidModificationError`);
+
+  promise_test(async t => {
+    const pc = new RTCPeerConnection();
+    t.add_cleanup(() => pc.close());
+    const { sender } = pc.addTransceiver('video', {sendEncodings: [{rid: "foo"}, {rid: "bar"}]});
+
+    const param = sender.getParameters();
+
+    const { encodings } = param;
+    assert_equals(encodings.length, 2);
+    encodings.push(encodings.shift());
+    assert_equals(param.encodings.length, 2);
+
+    return promise_rejects_dom(t, 'InvalidModificationError',
+      sender.setParameters(param));
+  }, `sender.setParameters() with reordered encodings should reject with InvalidModificationError`);
+
+  promise_test(async t => {
+    const pc = new RTCPeerConnection();
+    t.add_cleanup(() => pc.close());
+    const { sender } = pc.addTransceiver('video');
+
+    const param = sender.getParameters();
+
+    delete param.encodings;
 
     return promise_rejects_js(t, TypeError,
       sender.setParameters(param));
@@ -187,11 +428,9 @@
     const { sender } = pc.addTransceiver('video', {
       sendEncodings: [{ rid: 'foo' }, { rid: 'baz' }],
     });
-    await doOfferAnswerExchange(t, pc);
 
     const param = sender.getParameters();
-    validateSenderRtpParameters(param);
-    const encoding = getFirstEncoding(param);
+    const encoding = param.encodings[0];
 
     assert_equals(encoding.rid, 'foo');
 
@@ -209,44 +448,68 @@
   promise_test(async t => {
     const pc = new RTCPeerConnection();
     t.add_cleanup(() => pc.close());
-    const { sender } = pc.addTransceiver('audio');
-    await doOfferAnswerExchange(t, pc);
+    const { sender } = pc.addTransceiver('video');
 
     const param = sender.getParameters();
-    validateSenderRtpParameters(param);
-    const encoding = getFirstEncoding(param);
+    const encoding = param.encodings[0];
 
     encoding.scaleResolutionDownBy = 0.5;
-    return promise_rejects_js(t, RangeError,
-      sender.setParameters(param));
+    await promise_rejects_js(t, RangeError, sender.setParameters(param));
+    encoding.scaleResolutionDownBy = 0;
+    await promise_rejects_js(t, RangeError, sender.setParameters(param));
+    encoding.scaleResolutionDownBy = -1;
+    await promise_rejects_js(t, RangeError, sender.setParameters(param));
   }, `setParameters() with encoding.scaleResolutionDownBy field set to less than 1.0 should reject with RangeError`);
 
   promise_test(async t => {
     const pc = new RTCPeerConnection();
     t.add_cleanup(() => pc.close());
     const { sender } = pc.addTransceiver('video');
-    await doOfferAnswerExchange(t, pc);
+
+    let param = sender.getParameters();
+    const encoding = param.encodings[0];
+
+    delete encoding.scaleResolutionDownBy;
+    await sender.setParameters(param);
+    param = sender.getParameters();
+    assert_equals(param.encodings[0].scaleResolutionDownBy, 1.0);
+  }, `setParameters() with missing encoding.scaleResolutionDownBy field should succeed, and set the value back to 1`);
+
+  promise_test(async t => {
+    const pc = new RTCPeerConnection();
+    t.add_cleanup(() => pc.close());
+    const { sender } = pc.addTransceiver('video');
 
     const param = sender.getParameters();
-    validateSenderRtpParameters(param);
-    const encoding = getFirstEncoding(param);
+    const encoding = param.encodings[0];
 
     encoding.scaleResolutionDownBy = 1.5;
     return sender.setParameters(param)
     .then(() => {
       const param = sender.getParameters();
-      validateSenderRtpParameters(param);
-      const encoding = getFirstEncoding(param);
+      const encoding = param.encodings[0];
 
       assert_approx_equals(encoding.scaleResolutionDownBy, 1.5, 0.01);
     });
   }, `setParameters() with encoding.scaleResolutionDownBy field set to greater than 1.0 should succeed`);
 
+  test_modified_encoding('video', 'active', false, true,
+    'setParameters() with encoding.active false->true should succeed (video)');
+
+  test_modified_encoding('video', 'active', true, false,
+    'setParameters() with encoding.active true->false should succeed (video)');
+
+  test_modified_encoding('video', 'maxBitrate', 10000, 20000,
+    'setParameters() with modified encoding.maxBitrate should succeed (video)');
+
   test_modified_encoding('audio', 'active', false, true,
-    'setParameters() with modified encoding.active should succeed');
+    'setParameters() with encoding.active false->true should succeed (audio)');
+
+  test_modified_encoding('audio', 'active', true, false,
+    'setParameters() with encoding.active true->false should succeed (audio)');
 
   test_modified_encoding('audio', 'maxBitrate', 10000, 20000,
-    'setParameters() with modified encoding.maxBitrate should succeed');
+    'setParameters() with modified encoding.maxBitrate should succeed (audio)');
 
   test_modified_encoding('video', 'scaleResolutionDownBy', 2, 4,
     'setParameters() with modified encoding.scaleResolutionDownBy should succeed');
diff --git a/tests/wpt/web-platform-tests/webrtc/RTCRtpParameters-helper.js b/tests/wpt/web-platform-tests/webrtc/RTCRtpParameters-helper.js
index d7653c3a8af..dd8ae0cc06d 100644
--- a/tests/wpt/web-platform-tests/webrtc/RTCRtpParameters-helper.js
+++ b/tests/wpt/web-platform-tests/webrtc/RTCRtpParameters-helper.js
@@ -202,16 +202,6 @@ function validateCodecParameters(codec) {
   assert_optional_string_field(codec, 'sdpFmtpLine');
 }
 
-// Get the first encoding in param.encodings.
-// Asserts that param.encodings has at least one element.
-function getFirstEncoding(param) {
-  const {
-    encodings
-  } = param;
-  assert_equals(encodings.length, 1);
-  return encodings[0];
-}
-
 // Helper function to test that modifying an encoding field should succeed
 function test_modified_encoding(kind, field, value1, value2, desc) {
   promise_test(async t => {
@@ -228,7 +218,7 @@ function test_modified_encoding(kind, field, value1, value2, desc) {
 
     const param1 = sender.getParameters();
     validateSenderRtpParameters(param1);
-    const encoding1 = getFirstEncoding(param1);
+    const encoding1 = param1.encodings[0];
 
     assert_equals(encoding1[field], value1);
     encoding1[field] = value2;
@@ -236,7 +226,7 @@ function test_modified_encoding(kind, field, value1, value2, desc) {
     await sender.setParameters(param1);
     const param2 = sender.getParameters();
     validateSenderRtpParameters(param2);
-    const encoding2 = getFirstEncoding(param2);
+    const encoding2 = param2.encodings[0];
     assert_equals(encoding2[field], value2);
   }, desc + ' with RTCRtpTransceiverInit');
 
@@ -255,7 +245,7 @@ function test_modified_encoding(kind, field, value1, value2, desc) {
 
     const param1 = sender.getParameters();
     validateSenderRtpParameters(param1);
-    const encoding1 = getFirstEncoding(param1);
+    const encoding1 = param1.encodings[0];
 
     assert_equals(encoding1[field], value1);
     encoding1[field] = value2;
@@ -263,7 +253,7 @@ function test_modified_encoding(kind, field, value1, value2, desc) {
     await sender.setParameters(param1);
     const param2 = sender.getParameters();
     validateSenderRtpParameters(param2);
-    const encoding2 = getFirstEncoding(param2);
+    const encoding2 = param2.encodings[0];
     assert_equals(encoding2[field], value2);
   }, desc + ' without RTCRtpTransceiverInit');
 }
diff --git a/tests/wpt/web-platform-tests/webrtc/RTCRtpParameters-transactionId.html b/tests/wpt/web-platform-tests/webrtc/RTCRtpParameters-transactionId.html
index a7b7865532b..2aa43f48573 100644
--- a/tests/wpt/web-platform-tests/webrtc/RTCRtpParameters-transactionId.html
+++ b/tests/wpt/web-platform-tests/webrtc/RTCRtpParameters-transactionId.html
@@ -11,10 +11,6 @@
   // Test is based on the following editor draft:
   // https://w3c.github.io/webrtc-pc/archives/20170605/webrtc.html
 
-  // The following helper functions are called from RTCRtpParameters-helper.js:
-  //   doOfferAnswerExchange
-  //   validateSenderRtpParameters
-
   /*
     5.1.  RTCPeerConnection Interface Extensions
       partial interface RTCPeerConnection {
@@ -64,16 +60,53 @@
     const pc = new RTCPeerConnection();
     t.add_cleanup(() => pc.close());
     const { sender } = pc.addTransceiver('audio');
-    await doOfferAnswerExchange(t, pc);
 
     const param1 = sender.getParameters();
     const param2 = sender.getParameters();
+    assert_equals(typeof param1.transactionId, "string");
+    assert_greater_than(param1.transactionId.length, 0);
+    assert_equals(typeof param2.transactionId, "string");
+    assert_greater_than(param2.transactionId.length, 0);
+    assert_equals(param1.transactionId, param2.transactionId);
 
-    validateSenderRtpParameters(param1);
-    validateSenderRtpParameters(param2);
+    await undefined;
+    const param3 = sender.getParameters();
+    assert_equals(typeof param3.transactionId, "string");
+    assert_greater_than(param3.transactionId.length, 0);
+    assert_equals(param1.transactionId, param3.transactionId);
+  }, `sender.getParameters() should return the same transaction ID if called back-to-back without relinquishing the event loop, even if the microtask queue runs`);
+
+  test(t => {
+    const pc = new RTCPeerConnection();
+    t.add_cleanup(() => pc.close());
+    const { sender } = pc.addTransceiver('audio');
+
+    const param1 = sender.getParameters();
+    sender.setParameters(param1);
+    const param2 = sender.getParameters();
+    assert_equals(typeof param1.transactionId, "string");
+    assert_greater_than(param1.transactionId.length, 0);
+    assert_equals(typeof param2.transactionId, "string");
+    assert_greater_than(param2.transactionId.length, 0);
+
+    assert_equals(param1.transactionId, param2.transactionId);
+  }, `sender.getParameters() should return the same transaction ID if called back-to-back without relinquishing the event loop, even if there is an intervening call to setParameters`);
+
+  promise_test(async t => {
+    const pc = new RTCPeerConnection();
+    t.add_cleanup(() => pc.close());
+    const { sender } = pc.addTransceiver('audio');
+
+    const param1 = sender.getParameters();
+    await pc.createOffer();
+    const param2 = sender.getParameters();
+    assert_equals(typeof param1.transactionId, "string");
+    assert_greater_than(param1.transactionId.length, 0);
+    assert_equals(typeof param2.transactionId, "string");
+    assert_greater_than(param2.transactionId.length, 0);
 
     assert_not_equals(param1.transactionId, param2.transactionId);
-  }, `sender.getParameters() should return different transaction IDs for each call`);
+  }, `sender.getParameters() should return a different transaction ID if the event loop is relinquished between multiple calls`);
 
   /*
     5.2.  setParameters
@@ -88,15 +121,13 @@
     const pc = new RTCPeerConnection();
     t.add_cleanup(() => pc.close());
     const { sender } = pc.addTransceiver('audio');
-    await doOfferAnswerExchange(t, pc);
 
     const param = sender.getParameters();
-    validateSenderRtpParameters(param);
 
     const { transactionId } = param;
     param.transactionId = `${transactionId}-modified`;
 
-    return promise_rejects_dom(t, 'InvalidModificationError',
+    await promise_rejects_dom(t, 'InvalidModificationError',
       sender.setParameters(param));
   }, `sender.setParameters() with transaction ID different from last getParameters() should reject with InvalidModificationError`);
 
@@ -104,14 +135,12 @@
     const pc = new RTCPeerConnection();
     t.add_cleanup(() => pc.close());
     const { sender } = pc.addTransceiver('audio');
-    await doOfferAnswerExchange(t, pc);
 
     const param = sender.getParameters();
-    validateSenderRtpParameters(param);
 
-    param.transactionId = undefined;
+    delete param.transactionId;
 
-    return promise_rejects_js(t, TypeError,
+    await promise_rejects_js(t, TypeError,
       sender.setParameters(param));
   }, `sender.setParameters() with transaction ID unset should reject with TypeError`);
 
@@ -119,33 +148,39 @@
     const pc = new RTCPeerConnection();
     t.add_cleanup(() => pc.close());
     const { sender } = pc.addTransceiver('audio');
-    await doOfferAnswerExchange(t, pc);
 
     const param = sender.getParameters();
-    validateSenderRtpParameters(param);
 
-    return sender.setParameters(param)
-    .then(() =>
-      promise_rejects_dom(t, 'InvalidStateError',
-        sender.setParameters(param)));
+    await sender.setParameters(param);
+    await promise_rejects_dom(t, 'InvalidStateError', sender.setParameters(param))
   }, `setParameters() twice with the same parameters should reject with InvalidStateError`);
 
   promise_test(async t => {
     const pc = new RTCPeerConnection();
     t.add_cleanup(() => pc.close());
     const { sender } = pc.addTransceiver('audio');
-    await doOfferAnswerExchange(t, pc);
 
     const param1 = sender.getParameters();
+    // Queue a task, does not really matter what kind
+    await pc.createOffer();
     const param2 = sender.getParameters();
 
-    validateSenderRtpParameters(param1);
-    validateSenderRtpParameters(param2);
-
     assert_not_equals(param1.transactionId, param2.transactionId);
 
-    return promise_rejects_dom(t, 'InvalidModificationError',
+    await promise_rejects_dom(t, 'InvalidModificationError',
       sender.setParameters(param1));
   }, `setParameters() with parameters older than last getParameters() should reject with InvalidModificationError`);
 
+  promise_test(async t => {
+    const pc = new RTCPeerConnection();
+    t.add_cleanup(() => pc.close());
+    const { sender } = pc.addTransceiver('audio');
+
+    const param1 = sender.getParameters();
+    await pc.createOffer();
+
+    await promise_rejects_dom(t, 'InvalidStateError',
+      sender.setParameters(param1));
+  }, `setParameters() when the event loop has been relinquished since the last getParameters() should reject with InvalidStateError`);
+
 </script>
diff --git a/tests/wpt/web-platform-tests/webrtc/simulcast/negotiation-encodings.https.html b/tests/wpt/web-platform-tests/webrtc/simulcast/negotiation-encodings.https.html
new file mode 100644
index 00000000000..db690a9606c
--- /dev/null
+++ b/tests/wpt/web-platform-tests/webrtc/simulcast/negotiation-encodings.https.html
@@ -0,0 +1,436 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>RTCPeerConnection Simulcast Tests - negotiation/encodings</title>
+<meta name="timeout" content="long">
+<script src="../third_party/sdp/sdp.js"></script>
+<script src="simulcast.js"></script>
+<script src="../RTCPeerConnection-helper.js"></script>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="../../mediacapture-streams/permission-helper.js"></script>
+<script>
+
+promise_test(async t => {
+  const pc1 = new RTCPeerConnection();
+  t.add_cleanup(() => pc1.close());
+  const pc2 = new RTCPeerConnection();
+  t.add_cleanup(() => pc2.close());
+
+  const stream = await getNoiseStream({video: true});
+  t.add_cleanup(() => stream.getTracks().forEach(track => track.stop()));
+  const sender = pc1.addTrack(stream.getTracks()[0]);
+  // pc1 is unicast right now
+  pc2.addTrack(stream.getTracks()[0]);
+
+  await doOfferToRecvSimulcastAndAnswer(pc2, pc1, ["foo", "bar"]);
+  assert_equals(pc1.getTransceivers().length, 1);
+  const {encodings} = sender.getParameters();
+  const rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo", "bar"]);
+}, 'addTrack, then sRD(simulcast recv offer) results in simulcast');
+
+promise_test(async t => {
+  const pc1 = new RTCPeerConnection();
+  t.add_cleanup(() => pc1.close());
+  const pc2 = new RTCPeerConnection();
+  t.add_cleanup(() => pc2.close());
+
+  const stream = await getNoiseStream({audio: true});
+  t.add_cleanup(() => stream.getTracks().forEach(track => track.stop()));
+  const sender = pc1.addTrack(stream.getTracks()[0]);
+  // pc1 is unicast right now
+  pc2.addTrack(stream.getTracks()[0]);
+
+  await doOfferToRecvSimulcastAndAnswer(pc2, pc1, ["foo", "bar"]);
+  assert_equals(pc1.getTransceivers().length, 1);
+  const {encodings} = sender.getParameters();
+  const rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, [undefined]);
+}, 'simulcast is not supported for audio');
+
+// We do not have a test case for sRD(offer) narrowing a simulcast envelope
+// from addTransceiver, since that transceiver cannot be paired up with a remote
+// offer m-section
+promise_test(async t => {
+  const pc1 = new RTCPeerConnection();
+  t.add_cleanup(() => pc1.close());
+  const pc2 = new RTCPeerConnection();
+  t.add_cleanup(() => pc2.close());
+
+  const {sender} = pc1.addTransceiver("video", {sendEncodings: [{rid: "foo"}, {rid: "bar"}]});
+  let {encodings} = sender.getParameters();
+
+  await doOfferToSendSimulcastAndAnswer(pc1, pc2, ["foo"]);
+
+  assert_equals(pc1.getTransceivers().length, 1);
+  encodings = sender.getParameters().encodings;
+  const rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo"]);
+  const scaleDownByValues = encodings.map(({scaleResolutionDownBy}) => scaleResolutionDownBy);
+  assert_array_equals(scaleDownByValues, [2]);
+}, 'sRD(recv simulcast answer) can narrow the simulcast envelope specified by addTransceiver');
+
+promise_test(async t => {
+  const pc1 = new RTCPeerConnection();
+  t.add_cleanup(() => pc1.close());
+  const pc2 = new RTCPeerConnection();
+  t.add_cleanup(() => pc2.close());
+
+  const {sender} = pc1.addTransceiver("video", {sendEncodings: [{rid: "foo"}, {rid: "bar"}]});
+  let {encodings} = sender.getParameters();
+
+  await doOfferToSendSimulcastAndAnswer(pc1, pc2, ["foo", "bar"]);
+
+  assert_equals(pc1.getTransceivers().length, 1);
+  encodings = sender.getParameters().encodings;
+  let rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo", "bar"]);
+
+  await doOfferToSendSimulcastAndAnswer(pc1, pc2, ["foo"]);
+
+  assert_equals(pc1.getTransceivers().length, 1);
+  encodings = sender.getParameters().encodings;
+  rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo"]);
+  const scaleDownByValues = encodings.map(({scaleResolutionDownBy}) => scaleResolutionDownBy);
+  assert_array_equals(scaleDownByValues, [2]);
+}, 'sRD(recv simulcast answer) can narrow the simulcast envelope from a previous negotiation');
+
+promise_test(async t => {
+  const pc1 = new RTCPeerConnection();
+  t.add_cleanup(() => pc1.close());
+  const pc2 = new RTCPeerConnection();
+  t.add_cleanup(() => pc2.close());
+
+  const {sender} = pc1.addTransceiver("video", {sendEncodings: [{rid: "foo"}, {rid: "bar"}]});
+  let {encodings} = sender.getParameters();
+
+  await doOfferToSendSimulcastAndAnswer(pc1, pc2, ["foo", "bar"]);
+
+  assert_equals(pc1.getTransceivers().length, 1);
+  encodings = sender.getParameters().encodings;
+  let rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo", "bar"]);
+
+  // doAnswerToSendSimulcast causes pc2 to barf unless we set the direction to
+  // sendrecv
+  pc2.getTransceivers()[0].direction = "sendrecv";
+  pc2.getTransceivers()[1].direction = "sendrecv";
+
+  await doOfferToRecvSimulcast(pc2, pc1, ["foo"]);
+  assert_equals(pc1.getTransceivers().length, 1);
+  encodings = sender.getParameters().encodings;
+  rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo", "bar"], "[[SendEncodings]] is not updated in have-remote-offer for reoffers");
+
+  await doAnswerToSendSimulcast(pc2, pc1);
+
+  assert_equals(pc1.getTransceivers().length, 1);
+  encodings = sender.getParameters().encodings;
+  rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo"]);
+  const scaleDownByValues = encodings.map(({scaleResolutionDownBy}) => scaleResolutionDownBy);
+  assert_array_equals(scaleDownByValues, [2]);
+}, 'sRD(simulcast offer) can narrow the simulcast envelope from a previous negotiation');
+
+// https://github.com/w3c/webrtc-pc/issues/2780
+promise_test(async t => {
+  const pc1 = new RTCPeerConnection();
+  t.add_cleanup(() => pc1.close());
+  const pc2 = new RTCPeerConnection();
+  t.add_cleanup(() => pc2.close());
+
+  const stream = await getNoiseStream({video: true});
+  t.add_cleanup(() => stream.getTracks().forEach(track => track.stop()));
+  const sender = pc1.addTrack(stream.getTracks()[0]);
+  pc2.addTrack(stream.getTracks()[0]);
+
+  await doOfferToRecvSimulcastAndAnswer(pc2, pc1, ["foo", "bar", "foo"]);
+  assert_equals(pc1.getTransceivers().length, 1);
+  let {encodings} = sender.getParameters();
+  let rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo", "bar"]);
+  assert_true(pc1.remoteDescription.sdp.includes("a=simulcast:recv foo;bar;foo"), "Duplicate rids should be present in offer");
+  assert_false(pc1.localDescription.sdp.includes("a=simulcast:send foo;bar;foo"), "Duplicate rids should not be present in answer");
+  assert_true(pc1.localDescription.sdp.includes("a=simulcast:send foo;bar"), "Answer should use the correct rids");
+  assert_equals(pc1.getTransceivers().length, 1);
+  encodings = sender.getParameters().encodings;
+  rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo", "bar"]);
+}, 'Duplicate rids in sRD(offer) are ignored');
+
+// https://github.com/w3c/webrtc-pc/issues/2769
+promise_test(async t => {
+  const pc1 = new RTCPeerConnection();
+  t.add_cleanup(() => pc1.close());
+  const pc2 = new RTCPeerConnection();
+  t.add_cleanup(() => pc2.close());
+
+  const stream = await getNoiseStream({video: true});
+  t.add_cleanup(() => stream.getTracks().forEach(track => track.stop()));
+  const sender = pc1.addTrack(stream.getTracks()[0]);
+  pc2.addTrack(stream.getTracks()[0]);
+
+  await doOfferToRecvSimulcastAndAnswer(pc2, pc1, ["foo,bar", "1,2"]);
+  assert_equals(pc1.getTransceivers().length, 1);
+  let {encodings} = sender.getParameters();
+  let rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo", "1"]);
+  assert_true(pc1.remoteDescription.sdp.includes("a=simulcast:recv foo,bar;1,2"), "Choices of rids should be present in offer");
+  assert_true(pc1.localDescription.sdp.includes("a=simulcast:send foo;1\r\n"), "Choices of rids should not be present in answer");
+  assert_equals(pc1.getTransceivers().length, 1);
+  encodings = sender.getParameters().encodings;
+  rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo", "1"]);
+}, 'Choices in rids in sRD(offer) are ignored');
+
+// https://github.com/w3c/webrtc-pc/issues/2764
+promise_test(async t => {
+  const pc1 = new RTCPeerConnection();
+  t.add_cleanup(() => pc1.close());
+  const pc2 = new RTCPeerConnection();
+  t.add_cleanup(() => pc2.close());
+
+  const stream = await getNoiseStream({video: true});
+  t.add_cleanup(() => stream.getTracks().forEach(track => track.stop()));
+  const sender = pc1.addTrack(stream.getTracks()[0]);
+  pc2.addTrack(stream.getTracks()[0]);
+
+  await doOfferToRecvSimulcast(pc2, pc1, ["foo", "bar"]);
+  assert_equals(pc1.getTransceivers().length, 1);
+  let {encodings} = sender.getParameters();
+  let rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo", "bar"]);
+
+  await pc1.setRemoteDescription({sdp: "", type: "rollback"});
+
+  assert_equals(pc1.getTransceivers().length, 1);
+  encodings = sender.getParameters().encodings;
+  rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, [undefined]);
+}, 'addTrack, then rollback of sRD(simulcast offer), brings us back to having a single encoding without a rid');
+
+promise_test(async t => {
+  const pc1 = new RTCPeerConnection();
+  t.add_cleanup(() => pc1.close());
+  const pc2 = new RTCPeerConnection();
+  t.add_cleanup(() => pc2.close());
+
+  const stream = await getNoiseStream({video: true});
+  t.add_cleanup(() => stream.getTracks().forEach(track => track.stop()));
+  pc2.addTrack(stream.getTracks()[0]);
+  await doOfferToRecvSimulcast(pc2, pc1, ["foo", "bar"]);
+  const sender = pc1.addTrack(stream.getTracks()[0]);
+  assert_equals(pc1.getTransceivers().length, 1);
+
+  assert_equals(pc1.getTransceivers().length, 1);
+  let {encodings} = sender.getParameters();
+  let rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo", "bar"]);
+
+  await pc1.setRemoteDescription({sdp: "", type: "rollback"});
+
+  assert_equals(pc1.getTransceivers().length, 1);
+  encodings = sender.getParameters().encodings;
+  rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, [undefined]);
+}, 'sRD(simulcast offer), addTrack, then rollback brings us back to having a single encoding');
+
+promise_test(async t => {
+  const pc1 = new RTCPeerConnection();
+  t.add_cleanup(() => pc1.close());
+  const pc2 = new RTCPeerConnection();
+  t.add_cleanup(() => pc2.close());
+
+  const stream = await getNoiseStream({video: true});
+  t.add_cleanup(() => stream.getTracks().forEach(track => track.stop()));
+  const {sender} = pc1.addTransceiver(stream.getTracks()[0], {sendEncodings: [{rid: "foo"}, {rid: "bar"}]});
+
+  await doOfferToSendSimulcast(pc1, pc2);
+  await doAnswerToRecvSimulcast(pc1, pc2, ["bar", "foo"]);
+  assert_true(pc1.remoteDescription.sdp.includes("a=simulcast:recv bar;foo"), "Answer should have reordered rids");
+
+  assert_equals(pc1.getTransceivers().length, 1);
+  const {encodings} = sender.getParameters();
+  const rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo", "bar"]);
+}, 'Reordering of rids in sRD(answer) is ignored');
+
+promise_test(async t => {
+  const pc1 = new RTCPeerConnection();
+  t.add_cleanup(() => pc1.close());
+  const pc2 = new RTCPeerConnection();
+  t.add_cleanup(() => pc2.close());
+
+  const stream = await getNoiseStream({video: true});
+  t.add_cleanup(() => stream.getTracks().forEach(track => track.stop()));
+  const {sender} = pc1.addTransceiver(stream.getTracks()[0], {sendEncodings: [{rid: "foo"}, {rid: "bar"}]});
+
+  await doOfferToSendSimulcastAndAnswer(pc1, pc2, ["foo", "bar"]);
+
+  assert_equals(pc1.getTransceivers().length, 1);
+  let {encodings} = sender.getParameters();
+  let rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo", "bar"]);
+
+  await doOfferToSendSimulcast(pc1, pc2);
+  await doAnswerToRecvSimulcast(pc1, pc2, ["bar", "foo"]);
+  assert_true(pc1.remoteDescription.sdp.includes("a=simulcast:recv bar;foo"), "Answer should have reordered rids");
+
+  assert_equals(pc1.getTransceivers().length, 1);
+  encodings = sender.getParameters().encodings;
+  rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo", "bar"]);
+}, 'Reordering of rids in sRD(reanswer) is ignored');
+
+promise_test(async t => {
+  const pc1 = new RTCPeerConnection();
+  t.add_cleanup(() => pc1.close());
+  const pc2 = new RTCPeerConnection();
+  t.add_cleanup(() => pc2.close());
+
+  const stream = await getNoiseStream({video: true});
+  t.add_cleanup(() => stream.getTracks().forEach(track => track.stop()));
+  const {sender} = pc1.addTransceiver(stream.getTracks()[0], {sendEncodings: [{rid: "foo"}, {rid: "bar"}]});
+  await doOfferToSendSimulcastAndAnswer(pc1, pc2, ["foo", "bar"]);
+
+  assert_equals(pc1.getTransceivers().length, 1);
+  let {encodings} = sender.getParameters();
+  let rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo", "bar"]);
+
+  // doAnswerToSendSimulcast causes pc2 to barf unless we set the direction to
+  // sendrecv
+  pc2.getTransceivers()[0].direction = "sendrecv";
+  pc2.getTransceivers()[1].direction = "sendrecv";
+
+  await doOfferToRecvSimulcast(pc2, pc1, ["bar", "foo"]);
+  await doAnswerToSendSimulcast(pc2, pc1);
+  assert_true(pc1.remoteDescription.sdp.includes("a=simulcast:recv bar;foo"), "Reoffer should have reordered rids");
+
+  assert_equals(pc1.getTransceivers().length, 1);
+  encodings = sender.getParameters().encodings;
+  rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo", "bar"]);
+}, 'Reordering of rids in sRD(reoffer) is ignored');
+
+promise_test(async t => {
+  const pc1 = new RTCPeerConnection();
+  t.add_cleanup(() => pc1.close());
+  const pc2 = new RTCPeerConnection();
+  t.add_cleanup(() => pc2.close());
+
+  const stream = await getNoiseStream({video: true});
+  t.add_cleanup(() => stream.getTracks().forEach(track => track.stop()));
+  const {sender} = pc1.addTransceiver(stream.getTracks()[0], {sendEncodings: [{rid: "foo"}, {rid: "bar"}]});
+  await doOfferToSendSimulcastAndAnswer(pc1, pc2, ["foo", "bar"]);
+
+  assert_equals(pc1.getTransceivers().length, 1);
+  let encodings = sender.getParameters().encodings;
+  let rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo", "bar"]);
+
+  // doAnswerToSendSimulcast causes pc2 to barf unless we set the direction to
+  // sendrecv
+  pc2.getTransceivers()[0].direction = "sendrecv";
+  pc2.getTransceivers()[1].direction = "sendrecv";
+
+  // Keep the second encoding!
+  await doOfferToRecvSimulcast(pc2, pc1, ["bar"]);
+  assert_equals(pc1.getTransceivers().length, 1);
+  encodings = sender.getParameters().encodings;
+  rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo", "bar"]);
+
+  await pc1.setRemoteDescription({sdp: "", type: "rollback"});
+
+  encodings = sender.getParameters().encodings;
+  rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo", "bar"]);
+}, 'Rollback of sRD(reoffer) with a single rid results in all previous encodings');
+
+promise_test(async t => {
+  const pc1 = new RTCPeerConnection();
+  t.add_cleanup(() => pc1.close());
+  const pc2 = new RTCPeerConnection();
+  t.add_cleanup(() => pc2.close());
+
+  const {sender} = pc1.addTransceiver("video", {sendEncodings: [{rid: "foo"}, {rid: "bar"}]});
+  let {encodings} = sender.getParameters();
+
+  await doOfferToSendSimulcastAndAnswer(pc1, pc2, ["bar"]);
+
+  assert_equals(pc1.getTransceivers().length, 1);
+  encodings = sender.getParameters().encodings;
+  const rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["bar"]);
+  const scaleDownByValues = encodings.map(({scaleResolutionDownBy}) => scaleResolutionDownBy);
+  assert_array_equals(scaleDownByValues, [1]);
+}, 'sRD(recv simulcast answer) can narrow the simulcast envelope specified by addTransceiver by removing the first encoding');
+
+promise_test(async t => {
+  const pc1 = new RTCPeerConnection();
+  t.add_cleanup(() => pc1.close());
+  const pc2 = new RTCPeerConnection();
+  t.add_cleanup(() => pc2.close());
+
+  const {sender} = pc1.addTransceiver("video", {sendEncodings: [{rid: "foo"}, {rid: "bar"}]});
+  let {encodings} = sender.getParameters();
+
+  await doOfferToSendSimulcastAndAnswer(pc1, pc2, ["foo", "bar"]);
+
+  assert_equals(pc1.getTransceivers().length, 1);
+  encodings = sender.getParameters().encodings;
+  let rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo", "bar"]);
+
+  await doOfferToSendSimulcastAndAnswer(pc1, pc2, ["bar"]);
+
+  assert_equals(pc1.getTransceivers().length, 1);
+  encodings = sender.getParameters().encodings;
+  rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["bar"]);
+  const scaleDownByValues = encodings.map(({scaleResolutionDownBy}) => scaleResolutionDownBy);
+  assert_array_equals(scaleDownByValues, [1]);
+}, 'sRD(recv simulcast answer) can narrow the simulcast envelope from a previous negotiation by removing the first encoding');
+
+promise_test(async t => {
+  const pc1 = new RTCPeerConnection();
+  t.add_cleanup(() => pc1.close());
+  const pc2 = new RTCPeerConnection();
+  t.add_cleanup(() => pc2.close());
+
+  const {sender} = pc1.addTransceiver("video", {sendEncodings: [{rid: "foo"}, {rid: "bar"}]});
+  let {encodings} = sender.getParameters();
+
+  await doOfferToSendSimulcastAndAnswer(pc1, pc2, ["foo", "bar"]);
+
+  assert_equals(pc1.getTransceivers().length, 1);
+  encodings = sender.getParameters().encodings;
+  let rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo", "bar"]);
+
+  // doAnswerToSendSimulcast causes pc2 to barf unless we set the direction to
+  // sendrecv
+  pc2.getTransceivers()[0].direction = "sendrecv";
+  pc2.getTransceivers()[1].direction = "sendrecv";
+
+  await doOfferToRecvSimulcast(pc2, pc1, ["bar"]);
+  assert_equals(pc1.getTransceivers().length, 1);
+  encodings = sender.getParameters().encodings;
+  rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo", "bar"], "[[SendEncodings]] is not updated in have-remote-offer for reoffers");
+
+  await doAnswerToSendSimulcast(pc2, pc1);
+
+  assert_equals(pc1.getTransceivers().length, 1);
+  encodings = sender.getParameters().encodings;
+  rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["bar"]);
+  const scaleDownByValues = encodings.map(({scaleResolutionDownBy}) => scaleResolutionDownBy);
+  assert_array_equals(scaleDownByValues, [1]);
+}, 'sRD(simulcast offer) can narrow the simulcast envelope from a previous negotiation by removing the first encoding');
+
+</script>
diff --git a/tests/wpt/web-platform-tests/webrtc/simulcast/setParameters-active.https.html b/tests/wpt/web-platform-tests/webrtc/simulcast/setParameters-active.https.html
index 86afa4082e2..36f096add38 100644
--- a/tests/wpt/web-platform-tests/webrtc/simulcast/setParameters-active.https.html
+++ b/tests/wpt/web-platform-tests/webrtc/simulcast/setParameters-active.https.html
@@ -24,6 +24,56 @@ async function queryReceiverStats(pc) {
   return inboundStats.map(s => s.framesDecoded);
 }
 
+promise_test(async t => {
+  const rids = [0, 1];
+  const pc1 = new RTCPeerConnection();
+  t.add_cleanup(() => pc1.close());
+  const pc2 = new RTCPeerConnection();
+  t.add_cleanup(() => pc2.close());
+
+  await negotiateSimulcastAndWaitForVideo(t, rids, pc1, pc2);
+
+  // Deactivate first sender.
+  const parameters = pc1.getSenders()[0].getParameters();
+  parameters.encodings[0].active = false;
+  await pc1.getSenders()[0].setParameters(parameters);
+
+  // Assert (almost) no new frames are received on the first encoding.
+  // Without any action we would expect to have received around 30fps.
+  await new Promise(resolve => t.step_timeout(resolve, 100)); // Wait a bit.
+  const initialStats = await queryReceiverStats(pc2);
+  await new Promise(resolve => t.step_timeout(resolve, 1000)); // Wait more.
+  const subsequentStats = await queryReceiverStats(pc2);
+
+  assert_equals(subsequentStats[0], initialStats[0]);
+  assert_greater_than(subsequentStats[1], initialStats[1]);
+}, 'Simulcast setParameters active=false on first encoding stops sending frames for that encoding');
+
+promise_test(async t => {
+  const rids = [0, 1];
+  const pc1 = new RTCPeerConnection();
+  t.add_cleanup(() => pc1.close());
+  const pc2 = new RTCPeerConnection();
+  t.add_cleanup(() => pc2.close());
+
+  await negotiateSimulcastAndWaitForVideo(t, rids, pc1, pc2);
+
+  // Deactivate second sender.
+  const parameters = pc1.getSenders()[0].getParameters();
+  parameters.encodings[1].active = false;
+  await pc1.getSenders()[0].setParameters(parameters);
+
+  // Assert (almost) no new frames are received on the second encoding.
+  // Without any action we would expect to have received around 30fps.
+  await new Promise(resolve => t.step_timeout(resolve, 100)); // Wait a bit.
+  const initialStats = await queryReceiverStats(pc2);
+  await new Promise(resolve => t.step_timeout(resolve, 1000)); // Wait more.
+  const subsequentStats = await queryReceiverStats(pc2);
+
+  assert_equals(subsequentStats[1], initialStats[1]);
+  assert_greater_than(subsequentStats[0], initialStats[0]);
+}, 'Simulcast setParameters active=false on second encoding stops sending frames for that encoding');
+
 promise_test(async t => {
   const rids = [0, 1];
   const pc1 = new RTCPeerConnection();
diff --git a/tests/wpt/web-platform-tests/webrtc/simulcast/setParameters-encodings.https.html b/tests/wpt/web-platform-tests/webrtc/simulcast/setParameters-encodings.https.html
new file mode 100644
index 00000000000..fb33529db6f
--- /dev/null
+++ b/tests/wpt/web-platform-tests/webrtc/simulcast/setParameters-encodings.https.html
@@ -0,0 +1,468 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>RTCPeerConnection Simulcast Tests - setParameters/encodings</title>
+<meta name="timeout" content="long">
+<script src="../third_party/sdp/sdp.js"></script>
+<script src="simulcast.js"></script>
+<script src="../RTCPeerConnection-helper.js"></script>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="../../mediacapture-streams/permission-helper.js"></script>
+<script>
+
+async function queueAWebrtcTask() {
+  const pc = new RTCPeerConnection();
+  pc.addTransceiver('audio');
+  await new Promise(r => pc.onnegotiationneeded = r);
+}
+
+promise_test(async t => {
+  const pc1 = new RTCPeerConnection();
+  t.add_cleanup(() => pc1.close());
+  const pc2 = new RTCPeerConnection();
+  t.add_cleanup(() => pc2.close());
+
+  const {sender} = pc1.addTransceiver("video", {sendEncodings: [{rid: "foo"}, {rid: "bar"}]});
+
+  await doOfferToSendSimulcast(pc1, pc2);
+
+  await pc2.setLocalDescription();
+  const simulcastAnswer = midToRid(pc2.localDescription, pc1.localDescription, ["foo"]);
+
+  const parameters = sender.getParameters();
+  parameters.encodings[1].scaleResolutionDownBy = 3.3;
+  const answerDone = pc1.setRemoteDescription({type: "answer", sdp: simulcastAnswer});
+  await sender.setParameters(parameters);
+  await answerDone;
+
+  assert_equals(pc1.getTransceivers().length, 1);
+  const {encodings} = sender.getParameters();
+  const rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo"]);
+}, 'sRD(simulcast answer) can narrow the simulcast envelope when interrupted by a setParameters');
+
+promise_test(async t => {
+  const pc1 = new RTCPeerConnection();
+  t.add_cleanup(() => pc1.close());
+  const pc2 = new RTCPeerConnection();
+  t.add_cleanup(() => pc2.close());
+
+  const {sender} = pc1.addTransceiver("video", {sendEncodings: [{rid: "foo"}, {rid: "bar"}]});
+
+  await doOfferToSendSimulcastAndAnswer(pc1, pc2, ["foo", "bar"]);
+
+  assert_equals(pc1.getTransceivers().length, 1);
+  let encodings = sender.getParameters().encodings;
+  let rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo", "bar"]);
+
+  const reoffer = await pc2.createOffer();
+  const simulcastSdp = midToRid(reoffer, pc1.localDescription, ["foo"]);
+
+  const parameters = sender.getParameters();
+  parameters.encodings[1].scaleResolutionDownBy = 3.3;
+  const reofferDone = pc1.setRemoteDescription({type: "offer", sdp: simulcastSdp});
+  await sender.setParameters(parameters);
+  await reofferDone;
+  await pc1.setLocalDescription();
+
+  encodings = sender.getParameters().encodings;
+  rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo"]);
+}, 'sRD(simulcast offer) can narrow the simulcast envelope when interrupted by a setParameters');
+
+promise_test(async t => {
+  const pc1 = new RTCPeerConnection();
+  t.add_cleanup(() => pc1.close());
+  const pc2 = new RTCPeerConnection();
+  t.add_cleanup(() => pc2.close());
+
+  const {sender} = pc1.addTransceiver("video", {sendEncodings: [{rid: "foo"}, {rid: "bar"}]});
+
+  const parameters = sender.getParameters();
+  parameters.encodings[0].scaleResolutionDownBy = 2.3;
+  parameters.encodings[1].scaleResolutionDownBy = 3.3;
+  await sender.setParameters(parameters);
+
+  await doOfferToSendSimulcast(pc1, pc2);
+  await doAnswerToRecvSimulcast(pc1, pc2, []);
+
+  assert_equals(pc1.getTransceivers().length, 1);
+  const encodings = sender.getParameters().encodings;
+  const rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo"]);
+  assert_equals(encodings[0].scaleResolutionDownBy, 2.3);
+}, 'a simulcast setParameters followed by a sRD(unicast answer) results in keeping the first encoding');
+
+promise_test(async t => {
+  const pc1 = new RTCPeerConnection();
+  t.add_cleanup(() => pc1.close());
+  const pc2 = new RTCPeerConnection();
+  t.add_cleanup(() => pc2.close());
+
+  const {sender} = pc1.addTransceiver("video", {sendEncodings: [{rid: "foo"}, {rid: "bar"}]});
+  await doOfferToSendSimulcast(pc1, pc2);
+
+  await pc2.setLocalDescription();
+  const unicastAnswer = midToRid(pc2.localDescription, pc1.localDescription, []);
+
+  const parameters = sender.getParameters();
+  parameters.encodings[0].scaleResolutionDownBy = 2.3;
+  parameters.encodings[1].scaleResolutionDownBy = 3.3;
+  const answerDone = pc1.setRemoteDescription({type: "answer", sdp: unicastAnswer});
+  await sender.setParameters(parameters);
+  await answerDone;
+
+  assert_equals(pc1.getTransceivers().length, 1);
+  const encodings = sender.getParameters().encodings;
+  const rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo"]);
+  assert_equals(encodings[0].scaleResolutionDownBy, 2.3);
+}, 'sRD(unicast answer) interrupted by setParameters(simulcast) results in keeping the first encoding');
+
+promise_test(async t => {
+  const pc1 = new RTCPeerConnection();
+  t.add_cleanup(() => pc1.close());
+  const pc2 = new RTCPeerConnection();
+  t.add_cleanup(() => pc2.close());
+
+  const {sender} = pc1.addTransceiver("video", {sendEncodings: [{rid: "foo"}, {rid: "bar"}]});
+
+  await doOfferToSendSimulcastAndAnswer(pc1, pc2, ["foo", "bar"]);
+  assert_equals(pc1.getTransceivers().length, 1);
+  let encodings = sender.getParameters().encodings;
+  let rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo", "bar"]);
+
+  const reoffer = await pc2.createOffer();
+  const unicastSdp = midToRid(reoffer, pc1.localDescription, []);
+  const parameters = sender.getParameters();
+  parameters.encodings[0].scaleResolutionDownBy = 2.3;
+  parameters.encodings[1].scaleResolutionDownBy = 3.3;
+  const reofferDone = pc1.setRemoteDescription({type: "offer", sdp: unicastSdp});
+  await sender.setParameters(parameters);
+  await reofferDone;
+  await pc1.setLocalDescription();
+
+  encodings = sender.getParameters().encodings;
+  rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo"]);
+  assert_equals(encodings[0].scaleResolutionDownBy, 2.3);
+}, 'sRD(unicast reoffer) interrupted by setParameters(simulcast) results in keeping the first encoding');
+
+promise_test(async t => {
+  const pc1 = new RTCPeerConnection();
+  t.add_cleanup(() => pc1.close());
+  const pc2 = new RTCPeerConnection();
+  t.add_cleanup(() => pc2.close());
+
+  const {sender} = pc1.addTransceiver("video", {sendEncodings: [{rid: "foo"}, {rid: "bar"}]});
+
+  await doOfferToSendSimulcast(pc1, pc2);
+  await pc2.setLocalDescription();
+  const simulcastAnswer = midToRid(pc2.localDescription, pc1.localDescription, ["foo"]);
+  const parameters = sender.getParameters();
+  parameters.encodings[0].scaleResolutionDownBy = 3.3;
+  const answerDone = pc1.setRemoteDescription({type: "answer", sdp: simulcastAnswer});
+  await sender.setParameters(parameters);
+  await answerDone;
+
+  const {encodings} = sender.getParameters();
+  assert_equals(encodings.length, 1);
+  assert_equals(encodings[0].scaleResolutionDownBy, 3.3);
+}, 'sRD(simulcast answer) interrupted by a setParameters does not result in losing modifications from the setParameters to the encodings that remain');
+
+const simulcastOffer = `v=0
+o=- 3840232462471583827 0 IN IP4 127.0.0.1
+s=-
+t=0 0
+a=group:BUNDLE 0
+a=msid-semantic: WMS
+m=video 9 UDP/TLS/RTP/SAVPF 96
+c=IN IP4 0.0.0.0
+a=rtcp:9 IN IP4 0.0.0.0
+a=ice-ufrag:Li6+
+a=ice-pwd:3C05CTZBRQVmGCAq7hVasHlT
+a=ice-options:trickle
+a=fingerprint:sha-256 5B:D3:8E:66:0E:7D:D3:F3:8E:E6:80:28:19:FC:55:AD:58:5D:B9:3D:A8:DE:45:4A:E7:87:02:F8:3C:0B:3B:B3
+a=setup:actpass
+a=mid:0
+a=extmap:4 urn:ietf:params:rtp-hdrext:sdes:rtp-stream-id
+a=recvonly
+a=rtcp-mux
+a=rtpmap:96 VP8/90000
+a=rtcp-fb:96 goog-remb
+a=rtcp-fb:96 transport-cc
+a=rtcp-fb:96 ccm fir
+a=rid:foo recv
+a=rid:bar recv
+a=simulcast:recv foo;bar
+`;
+
+promise_test(async t => {
+  const pc1 = new RTCPeerConnection();
+  t.add_cleanup(() => pc1.close());
+
+  const stream = await getNoiseStream({video: true});
+  t.add_cleanup(() => stream.getTracks().forEach(track => track.stop()));
+  const sender = pc1.addTrack(stream.getTracks()[0]);
+  const parameters = sender.getParameters();
+  parameters.encodings[0].scaleResolutionDownBy = 3.0;
+  await sender.setParameters(parameters);
+
+  await pc1.setRemoteDescription({type: "offer", sdp: simulcastOffer});
+
+  const {encodings} = sender.getParameters();
+  const rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo", "bar"]);
+  assert_equals(encodings[0].scaleResolutionDownBy, 2.0);
+  assert_equals(encodings[1].scaleResolutionDownBy, 1.0);
+}, 'addTrack, then a unicast setParameters, then sRD(simulcast offer) results in simulcast without the settings from setParameters');
+
+promise_test(async t => {
+  const pc1 = new RTCPeerConnection();
+  t.add_cleanup(() => pc1.close());
+
+  const stream = await getNoiseStream({video: true});
+  t.add_cleanup(() => stream.getTracks().forEach(track => track.stop()));
+  const sender = pc1.addTrack(stream.getTracks()[0]);
+  const parameters = sender.getParameters();
+  parameters.encodings[0].scaleResolutionDownBy = 3.0;
+
+  const offerDone = pc1.setRemoteDescription({type: "offer", sdp: simulcastOffer});
+  await sender.setParameters(parameters);
+  await offerDone;
+
+  const {encodings} = sender.getParameters();
+  const rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo", "bar"]);
+  assert_equals(encodings[0].scaleResolutionDownBy, 2.0);
+  assert_equals(encodings[1].scaleResolutionDownBy, 1.0);
+}, 'addTrack, then sRD(simulcast offer) interrupted by a unicast setParameters results in simulcast without the settings from setParameters');
+
+promise_test(async t => {
+  const pc1 = new RTCPeerConnection();
+  const pc2 = new RTCPeerConnection();
+  t.add_cleanup(() => pc1.close());
+  t.add_cleanup(() => pc2.close());
+
+  const stream = await getNoiseStream({video: true});
+  t.add_cleanup(() => stream.getTracks().forEach(track => track.stop()));
+  const {sender} = pc1.addTransceiver(stream.getTracks()[0], {sendEncodings: [{rid: "foo"}, {rid: "bar"}]});
+  await doOfferToSendSimulcastAndAnswer(pc1, pc2, ["foo", "bar"]);
+  pc2.getTransceivers()[0].direction = "sendrecv";
+  pc2.getTransceivers()[1].direction = "sendrecv";
+
+  await doOfferToRecvSimulcast(pc2, pc1, []);
+  // Race simulcast setParameters against sLD(unicast reanswer)
+  const answer = await pc1.createAnswer();
+  const aTask = queueAWebrtcTask();
+  // This also queues a task to clear [[LastReturnedParameters]]
+  const parameters = sender.getParameters();
+  // This might or might not queue a task right away (it might do some
+  // microtask stuff first), but it doesn't really matter.
+  const sLDDone = pc1.setLocalDescription(answer);
+  await aTask;
+  // Task queue should now have the task that clears
+  // [[LastReturnedParameters]], _then_ the success task for sLD.
+  // setParameters should succeed because [[LastReturnedParameters]] has not
+  // yet been cleared, and the steps in the success task for sLD have not run
+  // either.
+  await sender.setParameters(parameters);
+  await sLDDone;
+
+  assert_equals(pc1.getTransceivers().length, 1);
+  const {encodings} = sender.getParameters();
+  const rids = encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo"]);
+}, 'getParameters, then sLD(unicast answer) interrupted by a simulcast setParameters results in unicast');
+
+promise_test(async t => {
+  const pc1 = new RTCPeerConnection();
+  const pc2 = new RTCPeerConnection();
+  t.add_cleanup(() => pc1.close());
+  t.add_cleanup(() => pc2.close());
+
+  const stream = await getNoiseStream({video: true});
+  t.add_cleanup(() => stream.getTracks().forEach(track => track.stop()));
+  const {sender} = pc1.addTransceiver(stream.getTracks()[0], {sendEncodings: [{rid: "foo"}, {rid: "bar"}]});
+  await doOfferToSendSimulcastAndAnswer(pc1, pc2, ["foo", "bar"]);
+  pc2.getTransceivers()[0].direction = "sendrecv";
+  pc2.getTransceivers()[1].direction = "sendrecv";
+
+  await doOfferToRecvSimulcast(pc2, pc1, []);
+  const answer = await pc1.createAnswer();
+
+  // The timing on this is very difficult. We want to ensure that our
+  // getParameters call happens after the initial steps in sLD, but
+  // before the queued task that sLD runs when it completes.
+  const aTask = queueAWebrtcTask();
+  const sLDDone = pc1.setLocalDescription(answer);
+  // We now have a queued task (aTask). We might also have the success task for
+  // sLD, but maybe not. Allowing aTask to finish gives us our best chance that
+  // the success task for sLD is queued, but not run yet.
+  await aTask;
+  const parameters = sender.getParameters();
+  // Hopefully we now have the success task for sLD, followed by the
+  // success task for getParameters.
+  await sLDDone;
+  // Success task for getParameters should not have run yet.
+  await promise_rejects_dom(t, 'InvalidStateError', sender.setParameters(parameters));
+},'Success task for setLocalDescription(answer) clears [[LastReturnedParameters]]');
+
+promise_test(async t => {
+  const pc1 = new RTCPeerConnection();
+  const pc2 = new RTCPeerConnection();
+  t.add_cleanup(() => pc1.close());
+  t.add_cleanup(() => pc2.close());
+
+  const stream = await getNoiseStream({video: true});
+  t.add_cleanup(() => stream.getTracks().forEach(track => track.stop()));
+  const {sender} = pc1.addTransceiver(stream.getTracks()[0], {sendEncodings: [{rid: "foo"}, {rid: "bar"}]});
+  await doOfferToSendSimulcastAndAnswer(pc1, pc2, ["foo", "bar"]);
+  pc2.getTransceivers()[0].direction = "sendrecv";
+  pc2.getTransceivers()[1].direction = "sendrecv";
+
+  await pc2.setLocalDescription();
+  const simulcastOffer = midToRid(
+    pc2.localDescription,
+    pc1.localDescription,
+    []
+  );
+
+  // The timing on this is very difficult. We need to ensure that our
+  // getParameters call happens after the initial steps in sRD, but
+  // before the queued task that sRD runs when it completes.
+  const aTask = queueAWebrtcTask();
+  const sRDDone = pc1.setRemoteDescription({ type: "offer", sdp: simulcastOffer });
+
+  await aTask;
+  const parameters = sender.getParameters();
+  await sRDDone;
+  await promise_rejects_dom(t, 'InvalidStateError', sender.setParameters(parameters));
+},'Success task for setRemoteDescription(offer) clears [[LastReturnedParameters]]');
+
+promise_test(async t => {
+  const pc1 = new RTCPeerConnection();
+  const pc2 = new RTCPeerConnection();
+  t.add_cleanup(() => pc1.close());
+  t.add_cleanup(() => pc2.close());
+
+  const stream = await getNoiseStream({video: true});
+  t.add_cleanup(() => stream.getTracks().forEach(track => track.stop()));
+  const {sender} = pc1.addTransceiver(stream.getTracks()[0], {sendEncodings: [{rid: "foo"}, {rid: "bar"}]});
+  await doOfferToSendSimulcastAndAnswer(pc1, pc2, ["foo", "bar"]);
+  pc2.getTransceivers()[0].direction = "sendrecv";
+  pc2.getTransceivers()[1].direction = "sendrecv";
+
+  await doOfferToSendSimulcast(pc1, pc2);
+  await pc2.setLocalDescription();
+  const simulcastAnswer = midToRid(
+    pc2.localDescription,
+    pc1.localDescription,
+    []
+  );
+
+  // The timing on this is very difficult. We need to ensure that our
+  // getParameters call happens after the initial steps in sRD, but
+  // before the queued task that sRD runs when it completes.
+  const aTask = queueAWebrtcTask();
+  const sRDDone = pc1.setRemoteDescription({ type: "answer", sdp: simulcastAnswer });
+  await aTask;
+
+  const parameters = sender.getParameters();
+  await sRDDone;
+  await promise_rejects_dom(t, 'InvalidStateError', sender.setParameters(parameters));
+},'Success task for setRemoteDescription(answer) clears [[LastReturnedParameters]]');
+
+promise_test(async t => {
+  const pc1 = new RTCPeerConnection();
+  t.add_cleanup(() => pc1.close());
+  const pc2 = new RTCPeerConnection();
+  t.add_cleanup(() => pc2.close());
+
+  const stream = await getNoiseStream({video: true});
+  t.add_cleanup(() => stream.getTracks().forEach(track => track.stop()));
+  const sender = pc1.addTrack(stream.getTracks()[0]);
+  pc2.addTrack(stream.getTracks()[0]);
+
+  await doOfferToRecvSimulcast(pc2, pc1, ["foo", "bar"]);
+  let parameters = sender.getParameters();
+  let rids = parameters.encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo", "bar"]);
+  parameters.encodings[0].scaleResolutionDownBy = 3;
+  parameters.encodings[1].scaleResolutionDownBy = 5;
+  await sender.setParameters(parameters);
+
+  await pc1.setRemoteDescription({sdp: "", type: "rollback"});
+
+  parameters = sender.getParameters();
+  rids = parameters.encodings.map(({rid}) => rid);
+  assert_array_equals(rids, [undefined]);
+  assert_equals(parameters.encodings[0].scaleResolutionDownBy, 1);
+}, 'addTrack, then rollback of sRD(simulcast offer), brings us back to having a single encoding without any previously set parameters');
+
+promise_test(async t => {
+  const pc1 = new RTCPeerConnection();
+  t.add_cleanup(() => pc1.close());
+  const pc2 = new RTCPeerConnection();
+  t.add_cleanup(() => pc2.close());
+
+  const stream = await getNoiseStream({video: true});
+  t.add_cleanup(() => stream.getTracks().forEach(track => track.stop()));
+  const {sender} = pc1.addTransceiver(stream.getTracks()[0], {sendEncodings: [{rid: "foo"}, {rid: "bar"}]});
+
+  await doOfferToSendSimulcastAndAnswer(pc1, pc2, ["foo", "bar"]);
+  let parameters = sender.getParameters();
+  let rids = parameters.encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo", "bar"]);
+  parameters.encodings[0].scaleResolutionDownBy = 3;
+  parameters.encodings[1].scaleResolutionDownBy = 5;
+  await sender.setParameters(parameters);
+
+  await doOfferToRecvSimulcast(pc2, pc1, []);
+  parameters = sender.getParameters();
+  rids = parameters.encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo", "bar"]);
+
+  await pc1.setRemoteDescription({sdp: "", type: "rollback"});
+  parameters = sender.getParameters();
+  rids = parameters.encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo", "bar"]);
+  assert_equals(parameters.encodings[0].scaleResolutionDownBy, 3);
+  assert_equals(parameters.encodings[1].scaleResolutionDownBy, 5);
+}, 'rollback of a remote offer that disabled a previously negotiated simulcast should restore simulcast along with any previously set parameters');
+
+promise_test(async t => {
+  const pc1 = new RTCPeerConnection();
+  t.add_cleanup(() => pc1.close());
+  const pc2 = new RTCPeerConnection();
+  t.add_cleanup(() => pc2.close());
+
+  const stream = await getNoiseStream({video: true});
+  t.add_cleanup(() => stream.getTracks().forEach(track => track.stop()));
+  const sender = pc1.addTrack(stream.getTracks()[0]);
+  pc2.addTrack(stream.getTracks()[0]);
+
+  await doOfferToRecvSimulcast(pc2, pc1, ["foo", "bar"]);
+  const aTask = queueAWebrtcTask();
+  let parameters = sender.getParameters();
+  let rids = parameters.encodings.map(({rid}) => rid);
+  assert_array_equals(rids, ["foo", "bar"]);
+  parameters.encodings[0].scaleResolutionDownBy = 3;
+  parameters.encodings[1].scaleResolutionDownBy = 5;
+
+  const rollbackDone = pc1.setRemoteDescription({sdp: "", type: "rollback"});
+  await aTask;
+  await sender.setParameters(parameters);
+  await rollbackDone;
+
+  parameters = sender.getParameters();
+  rids = parameters.encodings.map(({rid}) => rid);
+  assert_array_equals(rids, [undefined]);
+  assert_equals(parameters.encodings[0].scaleResolutionDownBy, 1);
+}, 'rollback of sRD(simulcast offer) interrupted by setParameters(simulcast) brings us back to having a single encoding without any previously set parameters');
+
+</script>
diff --git a/tests/wpt/web-platform-tests/webrtc/simulcast/simulcast.js b/tests/wpt/web-platform-tests/webrtc/simulcast/simulcast.js
index bede0a1d4e6..34605d4031d 100644
--- a/tests/wpt/web-platform-tests/webrtc/simulcast/simulcast.js
+++ b/tests/wpt/web-platform-tests/webrtc/simulcast/simulcast.js
@@ -7,75 +7,194 @@
  * which allows receiving the different spatial resolutions on separate
  * m-lines and tracks.
  */
-const extensionsToFilter = [
-  'urn:ietf:params:rtp-hdrext:sdes:mid',
-  'urn:ietf:params:rtp-hdrext:sdes:rtp-stream-id',
-  'urn:ietf:params:rtp-hdrext:sdes:repaired-rtp-stream-id',
+
+const ridExtensions = [
+  "urn:ietf:params:rtp-hdrext:sdes:rtp-stream-id",
+  "urn:ietf:params:rtp-hdrext:sdes:repaired-rtp-stream-id",
 ];
 
-function swapRidAndMidExtensionsInSimulcastOffer(offer, rids) {
-  const sections = SDPUtils.splitSections(offer.sdp);
+function ridToMid(description, rids) {
+  const sections = SDPUtils.splitSections(description.sdp);
   const dtls = SDPUtils.getDtlsParameters(sections[1], sections[0]);
   const ice = SDPUtils.getIceParameters(sections[1], sections[0]);
   const rtpParameters = SDPUtils.parseRtpParameters(sections[1]);
+  const setupValue = description.sdp.match(/a=setup:(.*)/)[1];
+  const directionValue =
+    description.sdp.match(/a=sendrecv|a=sendonly|a=recvonly|a=inactive/) ||
+    "a=sendrecv";
+  const mline = SDPUtils.parseMLine(sections[1]);
 
-  // The gist of this hack is that rid and mid have the same wire format.
-  const rid = rtpParameters.headerExtensions.find(ext => ext.uri === 'urn:ietf:params:rtp-hdrext:sdes:rtp-stream-id');
-  rtpParameters.headerExtensions = rtpParameters.headerExtensions.filter(ext => {
-    return !extensionsToFilter.includes(ext.uri);
-  });
-  // This tells the other side that the RID packets are actually mids.
-  rtpParameters.headerExtensions.push({id: rid.id, uri: 'urn:ietf:params:rtp-hdrext:sdes:mid', direction: 'sendrecv'});
+  // Skip mid extension; we are replacing it with the rid extmap
+  rtpParameters.headerExtensions = rtpParameters.headerExtensions.filter(
+    ext => ext.uri != "urn:ietf:params:rtp-hdrext:sdes:mid"
+  );
+
+  for (const ext of rtpParameters.headerExtensions) {
+    if (ext.uri == "urn:ietf:params:rtp-hdrext:sdes:rtp-stream-id") {
+      ext.uri = "urn:ietf:params:rtp-hdrext:sdes:mid";
+    }
+  }
 
   // Filter rtx as we have no way to (re)interpret rrid.
   // Not doing this makes probing use RTX, it's not understood and ramp-up is slower.
   rtpParameters.codecs = rtpParameters.codecs.filter(c => c.name.toUpperCase() !== 'RTX');
 
+  if (!rids) {
+    rids = Array.from(description.sdp.matchAll(/a=rid:(.*) send/g)).map(r => r[1]);
+  }
+
   let sdp = SDPUtils.writeSessionBoilerplate() +
-    SDPUtils.writeDtlsParameters(dtls, 'actpass') +
+    SDPUtils.writeDtlsParameters(dtls, setupValue) +
     SDPUtils.writeIceParameters(ice) +
     'a=group:BUNDLE ' + rids.join(' ') + '\r\n';
-  const baseRtpDescription = SDPUtils.writeRtpDescription('video', rtpParameters);
-  rids.forEach(rid => {
+  const baseRtpDescription = SDPUtils.writeRtpDescription(mline.kind, rtpParameters);
+  for (const rid of rids) {
     sdp += baseRtpDescription +
         'a=mid:' + rid + '\r\n' +
         'a=msid:rid-' + rid + ' rid-' + rid + '\r\n';
-  });
+    sdp += directionValue + "\r\n";
+  }
   return sdp;
 }
 
-function swapRidAndMidExtensionsInSimulcastAnswer(answer, localDescription, rids) {
-  const sections = SDPUtils.splitSections(answer.sdp);
+function midToRid(description, localDescription, rids) {
+  const sections = SDPUtils.splitSections(description.sdp);
   const dtls = SDPUtils.getDtlsParameters(sections[1], sections[0]);
   const ice = SDPUtils.getIceParameters(sections[1], sections[0]);
   const rtpParameters = SDPUtils.parseRtpParameters(sections[1]);
+  const setupValue = description.sdp.match(/a=setup:(.*)/)[1];
+  const directionValue =
+    description.sdp.match(/a=sendrecv|a=sendonly|a=recvonly|a=inactive/) ||
+    "a=sendrecv";
+  const mline = SDPUtils.parseMLine(sections[1]);
+
+  // Skip rid extensions; we are replacing them with the mid extmap
+  rtpParameters.headerExtensions = rtpParameters.headerExtensions.filter(
+    ext => !ridExtensions.includes(ext.uri)
+  );
+
+  for (const ext of rtpParameters.headerExtensions) {
+    if (ext.uri == "urn:ietf:params:rtp-hdrext:sdes:mid") {
+      ext.uri = "urn:ietf:params:rtp-hdrext:sdes:rtp-stream-id";
+    }
+  }
+
+  const localMid = localDescription ? SDPUtils.getMid(SDPUtils.splitSections(localDescription.sdp)[1]) : "0";
+
+  if (!rids) {
+    rids = [];
+    for (let i = 1; i < sections.length; i++) {
+      rids.push(SDPUtils.getMid(sections[i]));
+    }
+  }
 
-  rtpParameters.headerExtensions = rtpParameters.headerExtensions.filter(ext => {
-    return !extensionsToFilter.includes(ext.uri);
-  });
-  const localMid = SDPUtils.getMid(SDPUtils.splitSections(localDescription.sdp)[1]);
   let sdp = SDPUtils.writeSessionBoilerplate() +
-    SDPUtils.writeDtlsParameters(dtls, 'active') +
+    SDPUtils.writeDtlsParameters(dtls, setupValue) +
     SDPUtils.writeIceParameters(ice) +
     'a=group:BUNDLE ' + localMid + '\r\n';
-  sdp += SDPUtils.writeRtpDescription('video', rtpParameters);
+  sdp += SDPUtils.writeRtpDescription(mline.kind, rtpParameters);
+  // Although we are converting mids to rids, we still need a mid.
+  // The first one will be consistent with trickle ICE candidates.
   sdp += 'a=mid:' + localMid + '\r\n';
+  sdp += directionValue + "\r\n";
 
-  rids.forEach(rid => {
-    sdp += 'a=rid:' + rid + ' recv\r\n';
-  });
-  sdp += 'a=simulcast:recv ' + rids.join(';') + '\r\n';
+  for (const rid of rids) {
+    const stringrid = String(rid); // allow integers
+    const choices = stringrid.split(",");
+    choices.forEach(choice => {
+      sdp += 'a=rid:' + choice + ' recv\r\n';
+    });
+  }
+  if (rids.length) {
+    sdp += 'a=simulcast:recv ' + rids.join(';') + '\r\n';
+  }
 
-  // Re-add headerextensions we filtered.
-  const headerExtensions = SDPUtils.parseRtpParameters(SDPUtils.splitSections(localDescription.sdp)[1]).headerExtensions;
-  headerExtensions.forEach(ext => {
-    if (extensionsToFilter.includes(ext.uri)) {
-      sdp += 'a=extmap:' + ext.id + ' ' + ext.uri + '\r\n';
-    }
-  });
   return sdp;
 }
 
+async function doOfferToSendSimulcast(offerer, answerer) {
+  await offerer.setLocalDescription();
+
+  // Is this a renegotiation? If so, we cannot remove (or reorder!) any mids,
+  // even if some rids have been removed or reordered.
+  let mids = [];
+  if (answerer.localDescription) {
+    // Renegotiation. Mids must be the same as before, because renegotiation
+    // can never remove or reorder mids, nor can it expand the simulcast
+    // envelope.
+    mids = [...answerer.localDescription.sdp.matchAll(/a=mid:(.*)/g)].map(
+      e => e[1]
+    );
+  } else {
+    // First negotiation; the mids will be exactly the same as the rids
+    const simulcastAttr = offerer.localDescription.sdp.match(
+      /a=simulcast:send (.*)/
+    );
+    if (simulcastAttr) {
+      mids = simulcastAttr[1].split(";");
+    }
+  }
+
+  const nonSimulcastOffer = ridToMid(offerer.localDescription, mids);
+  await answerer.setRemoteDescription({
+    type: "offer",
+    sdp: nonSimulcastOffer,
+  });
+}
+
+async function doAnswerToRecvSimulcast(offerer, answerer, rids) {
+  await answerer.setLocalDescription();
+  const simulcastAnswer = midToRid(
+    answerer.localDescription,
+    offerer.localDescription,
+    rids
+  );
+  await offerer.setRemoteDescription({ type: "answer", sdp: simulcastAnswer });
+}
+
+async function doOfferToRecvSimulcast(offerer, answerer, rids) {
+  await offerer.setLocalDescription();
+  const simulcastOffer = midToRid(
+    offerer.localDescription,
+    answerer.localDescription,
+    rids
+  );
+  await answerer.setRemoteDescription({ type: "offer", sdp: simulcastOffer });
+}
+
+async function doAnswerToSendSimulcast(offerer, answerer) {
+  await answerer.setLocalDescription();
+
+  // See which mids the offerer had; it will barf if we remove or reorder them
+  const mids = [...offerer.localDescription.sdp.matchAll(/a=mid:(.*)/g)].map(
+    e => e[1]
+  );
+
+  const nonSimulcastAnswer = ridToMid(answerer.localDescription, mids);
+  await offerer.setRemoteDescription({
+    type: "answer",
+    sdp: nonSimulcastAnswer,
+  });
+}
+
+async function doOfferToSendSimulcastAndAnswer(offerer, answerer, rids) {
+  await doOfferToSendSimulcast(offerer, answerer);
+  await doAnswerToRecvSimulcast(offerer, answerer, rids);
+}
+
+async function doOfferToRecvSimulcastAndAnswer(offerer, answerer, rids) {
+  await doOfferToRecvSimulcast(offerer, answerer, rids);
+  await doAnswerToSendSimulcast(offerer, answerer);
+}
+
+function swapRidAndMidExtensionsInSimulcastOffer(offer, rids) {
+  return ridToMid(offer, rids);
+}
+
+function swapRidAndMidExtensionsInSimulcastAnswer(answer, localDescription, rids) {
+  return midToRid(answer, localDescription, rids);
+}
+
 async function negotiateSimulcastAndWaitForVideo(t, rids, pc1, pc2, codec) {
   exchangeIceCandidates(pc1, pc2);