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 3605e8f3fc9..76b44d9e9cf 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
deleted file mode 100644
index f64b45fea6b..00000000000
--- a/tests/wpt/metadata-layout-2020/css/CSS2/floats/hit-test-floats-002.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[hit-test-floats-002.html]
-  [Hit test float]
-    expected: FAIL
-
diff --git a/tests/wpt/metadata-layout-2020/css/CSS2/floats/hit-test-floats-003.html.ini b/tests/wpt/metadata-layout-2020/css/CSS2/floats/hit-test-floats-003.html.ini
deleted file mode 100644
index f29da48a2a0..00000000000
--- a/tests/wpt/metadata-layout-2020/css/CSS2/floats/hit-test-floats-003.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[hit-test-floats-003.html]
-  [Miss float below something else]
-    expected: FAIL
-
diff --git a/tests/wpt/metadata-layout-2020/css/CSS2/floats/hit-test-floats-005.html.ini b/tests/wpt/metadata-layout-2020/css/CSS2/floats/hit-test-floats-005.html.ini
deleted file mode 100644
index baa9f1a7541..00000000000
--- a/tests/wpt/metadata-layout-2020/css/CSS2/floats/hit-test-floats-005.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[hit-test-floats-005.html]
-  [Miss clipped float]
-    expected: FAIL
-
diff --git a/tests/wpt/metadata-layout-2020/css/css-animations/translation-animation-subpixel-offset.html.ini b/tests/wpt/metadata-layout-2020/css/css-animations/translation-animation-subpixel-offset.html.ini
new file mode 100644
index 00000000000..baebc61857a
--- /dev/null
+++ b/tests/wpt/metadata-layout-2020/css/css-animations/translation-animation-subpixel-offset.html.ini
@@ -0,0 +1,2 @@
+[translation-animation-subpixel-offset.html]
+  expected: TIMEOUT
diff --git a/tests/wpt/metadata-layout-2020/css/css-transforms/transform-scale-hittest.html.ini b/tests/wpt/metadata-layout-2020/css/css-transforms/transform-scale-hittest.html.ini
index 4a1e8110f6f..f8e7e539aae 100644
--- a/tests/wpt/metadata-layout-2020/css/css-transforms/transform-scale-hittest.html.ini
+++ b/tests/wpt/metadata-layout-2020/css/css-transforms/transform-scale-hittest.html.ini
@@ -2,3 +2,6 @@
   [Hit test intersecting scaled box]
     expected: FAIL
 
+  [Hit test within unscaled box]
+    expected: FAIL
+
diff --git a/tests/wpt/metadata-layout-2020/css/cssom-view/elementFromPoint-001.html.ini b/tests/wpt/metadata-layout-2020/css/cssom-view/elementFromPoint-001.html.ini
deleted file mode 100644
index e38782d8c85..00000000000
--- a/tests/wpt/metadata-layout-2020/css/cssom-view/elementFromPoint-001.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[elementFromPoint-001.html]
-  [CSSOM View - 5 - extensions to the Document interface]
-    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
new file mode 100644
index 00000000000..e181af5397f
--- /dev/null
+++ b/tests/wpt/metadata-layout-2020/css/cssom-view/elementsFromPoint-invalid-cases.html.ini
@@ -0,0 +1,4 @@
+[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-view/matchMedia-display-none-iframe.html.ini b/tests/wpt/metadata-layout-2020/css/cssom-view/matchMedia-display-none-iframe.html.ini
deleted file mode 100644
index e6e1f29e274..00000000000
--- a/tests/wpt/metadata-layout-2020/css/cssom-view/matchMedia-display-none-iframe.html.ini
+++ /dev/null
@@ -1,2 +0,0 @@
-[matchMedia-display-none-iframe.html]
-  expected: ERROR
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 a4bf3bc1094..b7172d06073 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
@@ -309,12 +309,6 @@
   [Response: combined response Content-Type: text/html;" \\" text/plain ";charset=GBK]
     expected: NOTRUN
 
-  [<iframe>: combined response Content-Type: text/html */*]
-    expected: FAIL
-
-  [<iframe>: separate response Content-Type: text/html;" text/plain]
-    expected: FAIL
-
   [<iframe>: separate response Content-Type: text/html */*;charset=gbk]
     expected: FAIL
 
@@ -324,3 +318,15 @@
   [<iframe>: combined response Content-Type: text/html;x=" text/plain]
     expected: FAIL
 
+  [<iframe>: combined response Content-Type: text/html;charset=gbk text/plain text/html]
+    expected: FAIL
+
+  [<iframe>: separate response Content-Type: text/html */*]
+    expected: FAIL
+
+  [<iframe>: separate response Content-Type: text/html;x=" text/plain]
+    expected: FAIL
+
+  [<iframe>: separate response Content-Type: text/plain */*;charset=gbk]
+    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 30e1b851fd4..ec1fd06e1f5 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
@@ -11,3 +11,6 @@
   [X-Content-Type-Options%3A%20nosniff%2C%2C%40%23%24%23%25%25%26%5E%26%5E*()()11!]
     expected: FAIL
 
+  [X-Content-Type-Options%3A%0D%0AX-Content-Type-Options%3A%20nosniff]
+    expected: FAIL
+
diff --git a/tests/wpt/metadata-layout-2020/html/browsers/history/the-history-interface/traverse_the_history_1.html.ini b/tests/wpt/metadata-layout-2020/html/browsers/history/the-history-interface/traverse_the_history_1.html.ini
deleted file mode 100644
index 87b07c3e670..00000000000
--- a/tests/wpt/metadata-layout-2020/html/browsers/history/the-history-interface/traverse_the_history_1.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[traverse_the_history_1.html]
-  [Multiple history traversals from the same task]
-    expected: FAIL
-
diff --git a/tests/wpt/metadata-layout-2020/html/browsers/history/the-history-interface/traverse_the_history_5.html.ini b/tests/wpt/metadata-layout-2020/html/browsers/history/the-history-interface/traverse_the_history_5.html.ini
new file mode 100644
index 00000000000..dc2e45516de
--- /dev/null
+++ b/tests/wpt/metadata-layout-2020/html/browsers/history/the-history-interface/traverse_the_history_5.html.ini
@@ -0,0 +1,4 @@
+[traverse_the_history_5.html]
+  [Multiple history traversals, last would be aborted]
+    expected: FAIL
+
diff --git a/tests/wpt/metadata-layout-2020/html/browsers/windows/embedded-opener-remove-frame.html.ini b/tests/wpt/metadata-layout-2020/html/browsers/windows/embedded-opener-remove-frame.html.ini
index b91c29e0274..8e2b6af33d8 100644
--- a/tests/wpt/metadata-layout-2020/html/browsers/windows/embedded-opener-remove-frame.html.ini
+++ b/tests/wpt/metadata-layout-2020/html/browsers/windows/embedded-opener-remove-frame.html.ini
@@ -1,4 +1,8 @@
 [embedded-opener-remove-frame.html]
+  expected: TIMEOUT
   [opener of discarded nested browsing context]
     expected: FAIL
 
+  [opener of discarded auxiliary browsing context]
+    expected: TIMEOUT
+
diff --git a/tests/wpt/metadata-layout-2020/html/rendering/non-replaced-elements/the-fieldset-and-legend-elements/fieldset-border-radius-with-alpha.html.ini b/tests/wpt/metadata-layout-2020/html/rendering/non-replaced-elements/the-fieldset-and-legend-elements/fieldset-border-radius-with-alpha.html.ini
new file mode 100644
index 00000000000..c39bc253c73
--- /dev/null
+++ b/tests/wpt/metadata-layout-2020/html/rendering/non-replaced-elements/the-fieldset-and-legend-elements/fieldset-border-radius-with-alpha.html.ini
@@ -0,0 +1,2 @@
+[fieldset-border-radius-with-alpha.html]
+  expected: FAIL
diff --git a/tests/wpt/metadata-layout-2020/html/semantics/embedded-content/image-maps/image-map-processing-model/hash-name-reference.html.ini b/tests/wpt/metadata-layout-2020/html/semantics/embedded-content/image-maps/image-map-processing-model/hash-name-reference.html.ini
index 09ae27d7480..5c3ac06f42a 100644
--- a/tests/wpt/metadata-layout-2020/html/semantics/embedded-content/image-maps/image-map-processing-model/hash-name-reference.html.ini
+++ b/tests/wpt/metadata-layout-2020/html/semantics/embedded-content/image-maps/image-map-processing-model/hash-name-reference.html.ini
@@ -171,6 +171,3 @@
   [XHTML img usemap="#hash-id"]
     expected: FAIL
 
-  [HTML (standards) IMG usemap="no-hash-name"]
-    expected: FAIL
-
diff --git a/tests/wpt/metadata-layout-2020/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_escaping-1.html.ini b/tests/wpt/metadata-layout-2020/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_escaping-1.html.ini
index 88f4ddd0e9a..42ebcc9d57e 100644
--- a/tests/wpt/metadata-layout-2020/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_escaping-1.html.ini
+++ b/tests/wpt/metadata-layout-2020/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_escaping-1.html.ini
@@ -1,5 +1,5 @@
 [iframe_sandbox_popups_escaping-1.html]
-  expected: CRASH
+  expected: TIMEOUT
   [Check that popups from a sandboxed iframe escape the sandbox if\n       allow-popups-to-escape-sandbox is used]
     expected: TIMEOUT
 
diff --git a/tests/wpt/metadata-layout-2020/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_escaping-3.html.ini b/tests/wpt/metadata-layout-2020/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_escaping-3.html.ini
index 295031c1812..338d283eb0e 100644
--- a/tests/wpt/metadata-layout-2020/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_escaping-3.html.ini
+++ b/tests/wpt/metadata-layout-2020/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_escaping-3.html.ini
@@ -1,5 +1,4 @@
 [iframe_sandbox_popups_escaping-3.html]
-  expected: TIMEOUT
   [Check that popups from a sandboxed iframe escape the sandbox if\n       allow-popups-to-escape-sandbox is used]
-    expected: TIMEOUT
+    expected: FAIL
 
diff --git a/tests/wpt/metadata-layout-2020/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_nonescaping-3.html.ini b/tests/wpt/metadata-layout-2020/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_nonescaping-3.html.ini
index 7d2b5231af2..f4f994c5d6f 100644
--- a/tests/wpt/metadata-layout-2020/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_nonescaping-3.html.ini
+++ b/tests/wpt/metadata-layout-2020/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_nonescaping-3.html.ini
@@ -1,5 +1,5 @@
 [iframe_sandbox_popups_nonescaping-3.html]
-  expected: CRASH
+  expected: TIMEOUT
   [Check that popups from a sandboxed iframe do not escape the sandbox]
-    expected: FAIL
+    expected: NOTRUN
 
diff --git a/tests/wpt/metadata-layout-2020/html/semantics/forms/form-submission-0/form-double-submit-2.html.ini b/tests/wpt/metadata-layout-2020/html/semantics/forms/form-submission-0/form-double-submit-2.html.ini
deleted file mode 100644
index 633a99517d3..00000000000
--- a/tests/wpt/metadata-layout-2020/html/semantics/forms/form-submission-0/form-double-submit-2.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[form-double-submit-2.html]
-  [preventDefault should allow onclick submit() to succeed]
-    expected: FAIL
-
diff --git a/tests/wpt/metadata-layout-2020/html/semantics/forms/form-submission-0/form-double-submit-3.html.ini b/tests/wpt/metadata-layout-2020/html/semantics/forms/form-submission-0/form-double-submit-3.html.ini
new file mode 100644
index 00000000000..9f416703229
--- /dev/null
+++ b/tests/wpt/metadata-layout-2020/html/semantics/forms/form-submission-0/form-double-submit-3.html.ini
@@ -0,0 +1,4 @@
+[form-double-submit-3.html]
+  [<button> should have the same double-submit protection as <input type=submit>]
+    expected: FAIL
+
diff --git a/tests/wpt/metadata-layout-2020/html/semantics/forms/form-submission-0/form-double-submit.html.ini b/tests/wpt/metadata-layout-2020/html/semantics/forms/form-submission-0/form-double-submit.html.ini
new file mode 100644
index 00000000000..b193c33c2b6
--- /dev/null
+++ b/tests/wpt/metadata-layout-2020/html/semantics/forms/form-submission-0/form-double-submit.html.ini
@@ -0,0 +1,4 @@
+[form-double-submit.html]
+  [default submit action should supersede onclick submit()]
+    expected: FAIL
+
diff --git a/tests/wpt/metadata-layout-2020/html/webappapis/scripting/events/compile-event-handler-settings-objects.html.ini b/tests/wpt/metadata-layout-2020/html/webappapis/scripting/events/compile-event-handler-settings-objects.html.ini
index dbec6f2c2ff..450c88bd32b 100644
--- a/tests/wpt/metadata-layout-2020/html/webappapis/scripting/events/compile-event-handler-settings-objects.html.ini
+++ b/tests/wpt/metadata-layout-2020/html/webappapis/scripting/events/compile-event-handler-settings-objects.html.ini
@@ -3,3 +3,6 @@
   [The incumbent settings object while executing the compiled callback via Web IDL's invoke must be that of the node document]
     expected: TIMEOUT
 
+  [The entry settings object while executing the compiled callback via Web IDL's invoke must be that of the node document]
+    expected: FAIL
+
diff --git a/tests/wpt/metadata-layout-2020/resource-timing/iframe-failed-commit.html.ini b/tests/wpt/metadata-layout-2020/resource-timing/iframe-failed-commit.html.ini
new file mode 100644
index 00000000000..e02284faa14
--- /dev/null
+++ b/tests/wpt/metadata-layout-2020/resource-timing/iframe-failed-commit.html.ini
@@ -0,0 +1,22 @@
+[iframe-failed-commit.html]
+  [Precondition]
+    expected: FAIL
+
+  [Test iframe redirecting to non-existent host]
+    expected: FAIL
+
+  [Cross-origin iframe that doesn't comply with CSP attribute gets reported]
+    expected: FAIL
+
+  [Same-origin iframe that complies with CSP attribute gets reported]
+    expected: FAIL
+
+  [Cross-origin iframe that complies with CSP attribute gets reported]
+    expected: FAIL
+
+  [Same-origin iframe that doesn't comply with CSP attribute gets reported]
+    expected: FAIL
+
+  [Test iframe from non-existent host]
+    expected: FAIL
+
diff --git a/tests/wpt/metadata-layout-2020/webaudio/the-audio-api/the-audiobuffersourcenode-interface/sub-sample-buffer-stitching.html.ini b/tests/wpt/metadata-layout-2020/webaudio/the-audio-api/the-audiobuffersourcenode-interface/sub-sample-buffer-stitching.html.ini
index 1434a9f2164..e32102c8943 100644
--- a/tests/wpt/metadata-layout-2020/webaudio/the-audio-api/the-audiobuffersourcenode-interface/sub-sample-buffer-stitching.html.ini
+++ b/tests/wpt/metadata-layout-2020/webaudio/the-audio-api/the-audiobuffersourcenode-interface/sub-sample-buffer-stitching.html.ini
@@ -374,3 +374,9 @@
   [X SNR (39.927354911150644 dB) is not greater than or equal to 65.737. Got 39.927354911150644.]
     expected: FAIL
 
+  [X SNR (-336.5274753602913 dB) is not greater than or equal to 65.737. Got -336.5274753602913.]
+    expected: FAIL
+
+  [X Stitched sine-wave buffers at sample rate 43800 does not equal [0,0.06264832615852356,0.12505052983760834,0.18696144223213196,0.24813786149024963,0.308339387178421,0.36732959747314453,0.4248766601085663,0.480754554271698,0.5347436666488647,0.5866320133209229,0.6362156271934509,0.6832997798919678,0.7276994585990906,0.7692402601242065,0.8077589869499207...\] with an element-wise tolerance of {"absoluteThreshold":0.0038986,"relativeThreshold":0}.\n\tIndex\tActual\t\t\tExpected\t\tAbsError\t\tRelError\t\tTest threshold\n\t[28696\]\t9.9558435935349637e+18\t9.3139332532882690e-1\t9.9558435935349637e+18\t1.0689193622919801e+19\t3.8985999999999999e-3\n\t[28697\]\t7.0477002859115601e-1\t9.0675884485244751e-1\t2.0198881626129150e-1\t2.2275913536212616e-1\t3.8985999999999999e-3\n\tMax AbsError of 9.9558435935349637e+18 at index of 28696.\n\tMax RelError of 1.0689193622919801e+19 at index of 28696.\n]
+    expected: FAIL
+
diff --git a/tests/wpt/metadata-layout-2020/webaudio/the-audio-api/the-audiocontext-interface/audiocontext-not-fully-active.html.ini b/tests/wpt/metadata-layout-2020/webaudio/the-audio-api/the-audiocontext-interface/audiocontext-not-fully-active.html.ini
index f1281b5ae81..b7e13cf7726 100644
--- a/tests/wpt/metadata-layout-2020/webaudio/the-audio-api/the-audiocontext-interface/audiocontext-not-fully-active.html.ini
+++ b/tests/wpt/metadata-layout-2020/webaudio/the-audio-api/the-audiocontext-interface/audiocontext-not-fully-active.html.ini
@@ -1,5 +1,4 @@
 [audiocontext-not-fully-active.html]
-  expected: TIMEOUT
   [frame in navigated remote-site frame]
     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 663a1f8fa30..00000000000
--- a/tests/wpt/metadata-layout-2020/webmessaging/with-ports/018.html.ini
+++ /dev/null
@@ -1,5 +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/workers/baseurl/alpha/sharedworker-in-worker.html.ini b/tests/wpt/metadata-layout-2020/workers/baseurl/alpha/sharedworker-in-worker.html.ini
index 333edb3a26e..650c91da4a6 100644
--- a/tests/wpt/metadata-layout-2020/workers/baseurl/alpha/sharedworker-in-worker.html.ini
+++ b/tests/wpt/metadata-layout-2020/workers/baseurl/alpha/sharedworker-in-worker.html.ini
@@ -1,4 +1,5 @@
 [sharedworker-in-worker.html]
+  expected: ERROR
   [Base URL in workers: new SharedWorker()]
     expected: FAIL
 
diff --git a/tests/wpt/metadata-layout-2020/workers/constructors/Worker/Worker-constructor.html.ini b/tests/wpt/metadata-layout-2020/workers/constructors/Worker/Worker-constructor.html.ini
deleted file mode 100644
index 80f9a4f15b8..00000000000
--- a/tests/wpt/metadata-layout-2020/workers/constructors/Worker/Worker-constructor.html.ini
+++ /dev/null
@@ -1,2 +0,0 @@
-[Worker-constructor.html]
-  expected: ERROR
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 faa00f45ecf..d4f62ed7113 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 9518cfee588..34fe8d27e6b 100644
--- a/tests/wpt/metadata/MANIFEST.json
+++ b/tests/wpt/metadata/MANIFEST.json
@@ -17393,15 +17393,6 @@
      ]
     ]
    },
-   "input-events": {
-    "input-events-cut-paste-manual.html": [
-     "4091c87cdd34720c29578b766b5791f8d68d4982",
-     [
-      null,
-      {}
-     ]
-    ]
-   },
    "mediacapture-depth": {
     "dictionary-manual.https.html": [
      "0a5b824881509baee240f385a9eeaa380a579948",
@@ -121654,6 +121645,19 @@
        ],
        {}
       ]
+     ],
+     "translation-animation-subpixel-offset.html": [
+      "5692a0823289811967e889969603cf8799cf7cf6",
+      [
+       null,
+       [
+        [
+         "/css/css-animations/translation-animation-subpixel-offset-ref.html",
+         "=="
+        ]
+       ],
+       {}
+      ]
      ]
     },
     "css-backgrounds": {
@@ -121844,7 +121848,7 @@
        ]
       ],
       "attachment-local-clipping-image-5.html": [
-       "ddd02dcfaefdd805188b1b9682f2070d6f81a976",
+       "1d6f1a8c6628a47e5421eb99769f56d53a74a08a",
        [
         null,
         [
@@ -121864,7 +121868,7 @@
             ],
             [
              0,
-             160
+             300
             ]
            ]
           ]
@@ -134577,6 +134581,19 @@
         ],
         {}
        ]
+      ],
+      "content-visibility-079.html": [
+       "9a8b46bf5c69507289150deb707b518234de8eab",
+       [
+        null,
+        [
+         [
+          "/css/css-contain/content-visibility/content-visibility-079-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
       ]
      },
      "counter-scoping-001.html": [
@@ -164906,6 +164923,32 @@
        {}
       ]
      ],
+     "no-scrollable-overflow-vertical-rl-2.html": [
+      "895f9bafc621329b95d1bb2fe086602945991cde",
+      [
+       null,
+       [
+        [
+         "/css/reference/ref-filled-green-100px-square-only.html",
+         "=="
+        ]
+       ],
+       {}
+      ]
+     ],
+     "no-scrollable-overflow-vertical-rl.html": [
+      "13385a2685cb8b6c33c94a9b09186336fda9c61a",
+      [
+       null,
+       [
+        [
+         "/css/reference/ref-filled-green-100px-square-only.html",
+         "=="
+        ]
+       ],
+       {}
+      ]
+     ],
      "overflow-body-propagation-001.html": [
       "0998fe68e007d5a46ff11d5ff87fdbad12d1dfe2",
       [
@@ -245334,7 +245377,7 @@
         ]
        ],
        "fieldset-border-radius-with-alpha.html": [
-        "36b9fc8c8ef7aa08473e4061c090042882b8b582",
+        "7a942076fbeaaee41c668ced609dee94906e56be",
         [
          null,
          [
@@ -257305,10 +257348,6 @@
      []
     ],
     "workflows": {
-     "detect_pull_request_preview.yml": [
-      "02870d8c7d223a371c09a97b5906610af191a5e4",
-      []
-     ],
      "documentation.yml": [
       "b8bf7972b0f7666f8a01a81b05e8dec432732225",
       []
@@ -257322,7 +257361,7 @@
       []
      ],
      "pull_request_previews.yml": [
-      "bf049dd9e63b0a8901bbf693a42fab2dfb621305",
+      "676aff3021242bb0d9b0ac49209088f48beca9fc",
       []
      ],
      "regen_certs.yml": [
@@ -300804,6 +300843,10 @@
      "transform-animation-under-large-scale-ref.html": [
       "14b41366268c3a33f2d49e477bab2d40c6acb432",
       []
+     ],
+     "translation-animation-subpixel-offset-ref.html": [
+      "5fc04d972b41d089b71d0c0baabc0d8e0d28c1d0",
+      []
      ]
     },
     "css-backgrounds": {
@@ -302846,6 +302889,10 @@
        "64629ca11977c77e4b1420881c5bc59a50816323",
        []
       ],
+      "content-visibility-079-ref.html": [
+       "416f23e8ca6aff4cd121a1c6b7a77945accd433e",
+       []
+      ],
       "inline-container-with-child-ref.html": [
        "af51cbd5db8f3eff56411345860548e95fe4d354",
        []
@@ -333190,7 +333237,7 @@
       []
      ],
      "testdriver-extension-tutorial.md": [
-      "0d73f9d41f8205802407aa32cdd5e11aae2c44f9",
+      "185a27f1a46af840f19395cab885451088130cb6",
       []
      ],
      "testdriver.md": [
@@ -338885,6 +338932,10 @@
        []
       ],
       "resources": {
+       "check-sandbox-flags.html": [
+        "0dc95315f164d693bd7bd0622880781f30bad7a1",
+        []
+       ],
        "post-done-to-opener.html": [
         "b47f0f274ef43148d3be418e2c0628a567f1c3c1",
         []
@@ -341026,7 +341077,7 @@
         []
        ],
        "redirect.py": [
-        "21a3dec9d224c1fca4a8815d9830d392c44cd18b",
+        "88dbd60fae7a41e245a0b822f8336ddeff56f410",
         []
        ],
        "report.py": [
@@ -341034,7 +341085,7 @@
         []
        ],
        "reporting-common.js": [
-        "3b1820cebb8f1d5f8b7fb00b90740cee6de9fbb9",
+        "01f835e12ad5f24c07c50ae7376183628fff80bc",
         []
        ],
        "test-access-property.js": [
@@ -345780,7 +345831,7 @@
         []
        ],
        "fieldset-border-radius-with-alpha-ref.html": [
-        "577482a328b47b72b78ddc22abef02e12836a378",
+        "5cfe13c40d465a5cd0cebfbafbb8db9d45491cbf",
         []
        ],
        "fieldset-containing-block-ref.html": [
@@ -351659,7 +351710,7 @@
    },
    "js-self-profiling": {
     "__dir__.headers": [
-     "63b60e490f47f4db77d33d7a4ca2f5b9a4181de8",
+     "35b10bd2ccdbfa99feb96079fafab61346d025ed",
      []
     ]
    },
@@ -357053,6 +357104,14 @@
       "dee5b62f0005705c18dde06865ab5a9947a37357",
       []
      ],
+     "csp-default-none.html": [
+      "1f59d8c2250f7f17f143887dc4f8e68cdf7faa83",
+      []
+     ],
+     "csp-default-none.html.headers": [
+      "d66f886dd23d44bb33750cb5723f3edb6b7930ab",
+      []
+     ],
      "document-domain-no-impact.sub.html": [
       "fbd7bc3b6e21ee39478c8a63780bb673dafe96a4",
       []
@@ -362266,7 +362325,7 @@
       []
      ],
      "pr_preview.py": [
-      "2396e9b8aee8a166c3b9321c7e9ec2e8f9b549c0",
+      "5bd2365164b98ba1a8c90a8d1a987fbaf8c97c73",
       []
      ],
      "regen_certs.py": [
@@ -362355,7 +362414,7 @@
        []
       ],
       "test_pr_preview.py": [
-       "ed6310c1ea129b19f313c29c98e5238a85546e42",
+       "87478727d3e20528fea165f0634df7d299d5a6ea",
        []
       ]
      },
@@ -370453,8 +370512,8 @@
    },
    "urlpattern": {
     "resources": {
-     "utils.js": [
-      "9132a52816e0c1cf0bc3a1b577d6611e65be8f6f",
+     "urlpatterntestdata.json": [
+      "66038e03d23bbb14f6d890a02e3e8dbefcb5aefe",
       []
      ]
     }
@@ -370898,7 +370957,7 @@
       ]
      },
      "generate-test-wbns.sh": [
-      "8fc28bb9db7cd9900bee9c3555e7e7d84e41b389",
+      "3c8a3ea68d60522452be94a7f8d0aaf9b11f5c55",
       []
      ],
      "location": {
@@ -370961,6 +371020,10 @@
        []
       ]
      },
+     "urn-uuid.har": [
+      "e0cea3699ae53beedde24dc55287b7d4407083dd",
+      []
+     ],
      "wbn": {
       "__dir__.headers": [
        "21e57b9caca1183ecda6f5d4fb9ebd556abf769a",
@@ -371019,6 +371082,10 @@
       "subresource.wbn": [
        "eabd994ff8bceaf4ef52b329b4faa158c292af12",
        []
+      ],
+      "urn-uuid.wbn": [
+       "a4bd3efc9cc73e1405bad5209631e0e1e1f352b5",
+       []
       ]
      }
     }
@@ -397200,7 +397267,7 @@
       ]
      ],
      "script-src-1_10.html": [
-      "a1bfdaeb15bfbadb322b393b34f6872de1c55699",
+      "fa25976c128f195828dbfdb2e7c068f72aa83f8e",
       [
        null,
        {}
@@ -415778,7 +415845,7 @@
       ]
      ],
      "fixed-layout-2.html": [
-      "7cb09d4dd04de1da380837b0b4c2e82cc1492f59",
+      "13a4664249f3a758858e190fa9361ffc6b2ed17b",
       [
        null,
        {}
@@ -458175,6 +458242,13 @@
         {}
        ]
       ],
+      "sandbox-initial-empty-document-toward-same-origin.html": [
+       "d1306c970322682f3979c497a5decd78218ba845",
+       [
+        null,
+        {}
+       ]
+      ],
       "sandbox-navigation-timing.tentative.html": [
        "686f1c0c9f6847772edbe2ef070a483db1df3d9d",
        [
@@ -496248,6 +496322,15 @@
       }
      ]
     ],
+    "input-events-cut-paste.html": [
+     "f2ca5a0a654f270d33d8662f4e8b25369cd98df7",
+     [
+      null,
+      {
+       "testdriver": true
+      }
+     ]
+    ],
     "input-events-exec-command.html": [
      "8f8493651e5af4b747d952ac786334ace8ed61c4",
      [
@@ -500396,7 +500479,18 @@
       null,
       {}
      ]
-    ]
+    ],
+    "mse-for-webcodecs": {
+     "tentative": {
+      "mediasource-webcodecs-addsourcebuffer.html": [
+       "a9dd7072b0758d58bac67c13dcb78c76dc6aa669",
+       [
+        null,
+        {}
+       ]
+      ]
+     }
+    }
    },
    "mediacapture-depth": {
     "idlharness.html": [
@@ -523278,6 +523372,13 @@
       }
      ]
     ],
+    "iframe-failed-commit.html": [
+     "75e19f788efb2ecbccf67c4df02f030e3d9415c7",
+     [
+      null,
+      {}
+     ]
+    ],
     "nested-context-navigations-embed.html": [
      "bbba46c50edf21f50b49099c779dd5a8792faa0f",
      [
@@ -537621,7 +537722,7 @@
      ]
     ],
     "block-string-assignment-to-DOMWindowTimers-setTimeout-setInterval.tentative.html": [
-     "f36ae94ea10ce95d7087ec22ef4a25f157f7e6a8",
+     "c24715718d17561f779c6df7098f4c0b874675a9",
      [
       null,
       {}
@@ -540521,127 +540622,48 @@
     ]
    },
    "urlpattern": {
-    "input.https.any.js": [
-     "71a8fb237b8101789828e1352dc516d97c7d509a",
+    "urlpattern.https.any.js": [
+     "27b03d0ff03261d50721edb7b22b8205e0610238",
      [
-      "urlpattern/input.https.any.html",
+      "urlpattern/urlpattern.https.any.html",
       {
        "script_metadata": [
         [
          "global",
          "window,worker"
-        ],
-        [
-         "script",
-         "resources/utils.js"
         ]
        ]
       }
      ],
      [
-      "urlpattern/input.https.any.serviceworker.html",
+      "urlpattern/urlpattern.https.any.serviceworker.html",
       {
        "script_metadata": [
         [
          "global",
          "window,worker"
-        ],
-        [
-         "script",
-         "resources/utils.js"
         ]
        ]
       }
      ],
      [
-      "urlpattern/input.https.any.sharedworker.html",
+      "urlpattern/urlpattern.https.any.sharedworker.html",
       {
        "script_metadata": [
         [
          "global",
          "window,worker"
-        ],
-        [
-         "script",
-         "resources/utils.js"
         ]
        ]
       }
      ],
      [
-      "urlpattern/input.https.any.worker.html",
+      "urlpattern/urlpattern.https.any.worker.html",
       {
        "script_metadata": [
         [
          "global",
          "window,worker"
-        ],
-        [
-         "script",
-         "resources/utils.js"
-        ]
-       ]
-      }
-     ]
-    ],
-    "pathname.https.any.js": [
-     "5de41ccc438de61af3dd396b3b67489059140f55",
-     [
-      "urlpattern/pathname.https.any.html",
-      {
-       "script_metadata": [
-        [
-         "global",
-         "window,worker"
-        ],
-        [
-         "script",
-         "resources/utils.js"
-        ]
-       ]
-      }
-     ],
-     [
-      "urlpattern/pathname.https.any.serviceworker.html",
-      {
-       "script_metadata": [
-        [
-         "global",
-         "window,worker"
-        ],
-        [
-         "script",
-         "resources/utils.js"
-        ]
-       ]
-      }
-     ],
-     [
-      "urlpattern/pathname.https.any.sharedworker.html",
-      {
-       "script_metadata": [
-        [
-         "global",
-         "window,worker"
-        ],
-        [
-         "script",
-         "resources/utils.js"
-        ]
-       ]
-      }
-     ],
-     [
-      "urlpattern/pathname.https.any.worker.html",
-      {
-       "script_metadata": [
-        [
-         "global",
-         "window,worker"
-        ],
-        [
-         "script",
-         "resources/utils.js"
         ]
        ]
       }
@@ -544797,7 +544819,7 @@
       ]
      ],
      "subresource-loading-from-web-bundle.tentative.html": [
-      "c2de0eb0994f54c65a342b501aa3e9107949faf7",
+      "53a9c1b2cc707271c8d7b0e7fb7385fd59839744",
       [
        null,
        {}
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
deleted file mode 100644
index f64b45fea6b..00000000000
--- a/tests/wpt/metadata/css/CSS2/floats/hit-test-floats-002.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[hit-test-floats-002.html]
-  [Hit test float]
-    expected: FAIL
-
diff --git a/tests/wpt/metadata/css/CSS2/floats/hit-test-floats-003.html.ini b/tests/wpt/metadata/css/CSS2/floats/hit-test-floats-003.html.ini
deleted file mode 100644
index f29da48a2a0..00000000000
--- a/tests/wpt/metadata/css/CSS2/floats/hit-test-floats-003.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[hit-test-floats-003.html]
-  [Miss float below something else]
-    expected: FAIL
-
diff --git a/tests/wpt/metadata/css/CSS2/floats/hit-test-floats-005.html.ini b/tests/wpt/metadata/css/CSS2/floats/hit-test-floats-005.html.ini
deleted file mode 100644
index baa9f1a7541..00000000000
--- a/tests/wpt/metadata/css/CSS2/floats/hit-test-floats-005.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[hit-test-floats-005.html]
-  [Miss clipped float]
-    expected: FAIL
-
diff --git a/tests/wpt/metadata/css/css-animations/translation-animation-subpixel-offset.html.ini b/tests/wpt/metadata/css/css-animations/translation-animation-subpixel-offset.html.ini
new file mode 100644
index 00000000000..baebc61857a
--- /dev/null
+++ b/tests/wpt/metadata/css/css-animations/translation-animation-subpixel-offset.html.ini
@@ -0,0 +1,2 @@
+[translation-animation-subpixel-offset.html]
+  expected: TIMEOUT
diff --git a/tests/wpt/metadata/css/css-transforms/transform-scale-hittest.html.ini b/tests/wpt/metadata/css/css-transforms/transform-scale-hittest.html.ini
index 4a1e8110f6f..f8e7e539aae 100644
--- a/tests/wpt/metadata/css/css-transforms/transform-scale-hittest.html.ini
+++ b/tests/wpt/metadata/css/css-transforms/transform-scale-hittest.html.ini
@@ -2,3 +2,6 @@
   [Hit test intersecting scaled box]
     expected: FAIL
 
+  [Hit test within unscaled box]
+    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
deleted file mode 100644
index e38782d8c85..00000000000
--- a/tests/wpt/metadata/css/cssom-view/elementFromPoint-001.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[elementFromPoint-001.html]
-  [CSSOM View - 5 - extensions to the Document interface]
-    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
new file mode 100644
index 00000000000..e181af5397f
--- /dev/null
+++ b/tests/wpt/metadata/css/cssom-view/elementsFromPoint-invalid-cases.html.ini
@@ -0,0 +1,4 @@
+[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-view/matchMedia-display-none-iframe.html.ini b/tests/wpt/metadata/css/cssom-view/matchMedia-display-none-iframe.html.ini
deleted file mode 100644
index e6e1f29e274..00000000000
--- a/tests/wpt/metadata/css/cssom-view/matchMedia-display-none-iframe.html.ini
+++ /dev/null
@@ -1,2 +0,0 @@
-[matchMedia-display-none-iframe.html]
-  expected: ERROR
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 9fd554c348a..c140cc820c5 100644
--- a/tests/wpt/metadata/fetch/content-type/response.window.js.ini
+++ b/tests/wpt/metadata/fetch/content-type/response.window.js.ini
@@ -309,12 +309,6 @@
   [fetch(): separate response Content-Type: text/plain ]
     expected: NOTRUN
 
-  [<iframe>: combined response Content-Type: text/html */*]
-    expected: FAIL
-
-  [<iframe>: separate response Content-Type: text/html;" text/plain]
-    expected: FAIL
-
   [<iframe>: separate response Content-Type: text/html */*;charset=gbk]
     expected: FAIL
 
@@ -324,3 +318,15 @@
   [<iframe>: combined response Content-Type: text/html;x=" text/plain]
     expected: FAIL
 
+  [<iframe>: combined response Content-Type: text/html;charset=gbk text/plain text/html]
+    expected: FAIL
+
+  [<iframe>: separate response Content-Type: text/html */*]
+    expected: FAIL
+
+  [<iframe>: separate response Content-Type: text/html;x=" text/plain]
+    expected: FAIL
+
+  [<iframe>: separate response Content-Type: text/plain */*;charset=gbk]
+    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 30e1b851fd4..ec1fd06e1f5 100644
--- a/tests/wpt/metadata/fetch/nosniff/parsing-nosniff.window.js.ini
+++ b/tests/wpt/metadata/fetch/nosniff/parsing-nosniff.window.js.ini
@@ -11,3 +11,6 @@
   [X-Content-Type-Options%3A%20nosniff%2C%2C%40%23%24%23%25%25%26%5E%26%5E*()()11!]
     expected: FAIL
 
+  [X-Content-Type-Options%3A%0D%0AX-Content-Type-Options%3A%20nosniff]
+    expected: FAIL
+
diff --git a/tests/wpt/metadata/html/browsers/history/the-history-interface/traverse_the_history_1.html.ini b/tests/wpt/metadata/html/browsers/history/the-history-interface/traverse_the_history_1.html.ini
deleted file mode 100644
index 87b07c3e670..00000000000
--- a/tests/wpt/metadata/html/browsers/history/the-history-interface/traverse_the_history_1.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[traverse_the_history_1.html]
-  [Multiple history traversals from the same task]
-    expected: FAIL
-
diff --git a/tests/wpt/metadata/html/browsers/history/the-history-interface/traverse_the_history_5.html.ini b/tests/wpt/metadata/html/browsers/history/the-history-interface/traverse_the_history_5.html.ini
new file mode 100644
index 00000000000..dc2e45516de
--- /dev/null
+++ b/tests/wpt/metadata/html/browsers/history/the-history-interface/traverse_the_history_5.html.ini
@@ -0,0 +1,4 @@
+[traverse_the_history_5.html]
+  [Multiple history traversals, last would be aborted]
+    expected: FAIL
+
diff --git a/tests/wpt/metadata/html/browsers/windows/embedded-opener-remove-frame.html.ini b/tests/wpt/metadata/html/browsers/windows/embedded-opener-remove-frame.html.ini
index 49b12655f9a..fd369192a02 100644
--- a/tests/wpt/metadata/html/browsers/windows/embedded-opener-remove-frame.html.ini
+++ b/tests/wpt/metadata/html/browsers/windows/embedded-opener-remove-frame.html.ini
@@ -1,7 +1,11 @@
 [embedded-opener-remove-frame.html]
+  expected: TIMEOUT
   [opener and "removed" embedded documents]
     expected: FAIL
 
   [opener of discarded nested browsing context]
     expected: FAIL
 
+  [opener of discarded auxiliary browsing context]
+    expected: TIMEOUT
+
diff --git a/tests/wpt/metadata/html/rendering/non-replaced-elements/the-fieldset-and-legend-elements/fieldset-border-radius-with-alpha.html.ini b/tests/wpt/metadata/html/rendering/non-replaced-elements/the-fieldset-and-legend-elements/fieldset-border-radius-with-alpha.html.ini
new file mode 100644
index 00000000000..c39bc253c73
--- /dev/null
+++ b/tests/wpt/metadata/html/rendering/non-replaced-elements/the-fieldset-and-legend-elements/fieldset-border-radius-with-alpha.html.ini
@@ -0,0 +1,2 @@
+[fieldset-border-radius-with-alpha.html]
+  expected: FAIL
diff --git a/tests/wpt/metadata/html/semantics/embedded-content/image-maps/image-map-processing-model/hash-name-reference.html.ini b/tests/wpt/metadata/html/semantics/embedded-content/image-maps/image-map-processing-model/hash-name-reference.html.ini
index 98163335e40..1de3f8d68b2 100644
--- a/tests/wpt/metadata/html/semantics/embedded-content/image-maps/image-map-processing-model/hash-name-reference.html.ini
+++ b/tests/wpt/metadata/html/semantics/embedded-content/image-maps/image-map-processing-model/hash-name-reference.html.ini
@@ -172,6 +172,3 @@
   [XHTML img usemap="http://example.org/#garbage-before-hash-id"]
     expected: FAIL
 
-  [HTML (standards) IMG usemap="no-hash-name"]
-    expected: FAIL
-
diff --git a/tests/wpt/metadata/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_escaping-1.html.ini b/tests/wpt/metadata/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_escaping-1.html.ini
index 2a166bb97b7..fc37df7e3fa 100644
--- a/tests/wpt/metadata/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_escaping-1.html.ini
+++ b/tests/wpt/metadata/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_escaping-1.html.ini
@@ -1,6 +1,6 @@
 [iframe_sandbox_popups_escaping-1.html]
   type: testharness
-  expected: CRASH
+  expected: TIMEOUT
   [Check that popups from a sandboxed iframe escape the sandbox if\n       allow-popups-to-escape-sandbox is used]
     expected: TIMEOUT
 
diff --git a/tests/wpt/metadata/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_escaping-3.html.ini b/tests/wpt/metadata/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_escaping-3.html.ini
index 5f60c78e73c..f6a7aca3306 100644
--- a/tests/wpt/metadata/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_escaping-3.html.ini
+++ b/tests/wpt/metadata/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_escaping-3.html.ini
@@ -1,6 +1,5 @@
 [iframe_sandbox_popups_escaping-3.html]
   type: testharness
-  expected: TIMEOUT
   [Check that popups from a sandboxed iframe escape the sandbox if\n       allow-popups-to-escape-sandbox is used]
-    expected: TIMEOUT
+    expected: FAIL
 
diff --git a/tests/wpt/metadata/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_nonescaping-3.html.ini b/tests/wpt/metadata/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_nonescaping-3.html.ini
index 7d2b5231af2..f4f994c5d6f 100644
--- a/tests/wpt/metadata/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_nonescaping-3.html.ini
+++ b/tests/wpt/metadata/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_nonescaping-3.html.ini
@@ -1,5 +1,5 @@
 [iframe_sandbox_popups_nonescaping-3.html]
-  expected: CRASH
+  expected: TIMEOUT
   [Check that popups from a sandboxed iframe do not escape the sandbox]
-    expected: FAIL
+    expected: NOTRUN
 
diff --git a/tests/wpt/metadata/html/semantics/forms/form-submission-0/form-double-submit-2.html.ini b/tests/wpt/metadata/html/semantics/forms/form-submission-0/form-double-submit-2.html.ini
deleted file mode 100644
index 633a99517d3..00000000000
--- a/tests/wpt/metadata/html/semantics/forms/form-submission-0/form-double-submit-2.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[form-double-submit-2.html]
-  [preventDefault should allow onclick submit() to succeed]
-    expected: FAIL
-
diff --git a/tests/wpt/metadata/html/semantics/forms/form-submission-0/form-double-submit-3.html.ini b/tests/wpt/metadata/html/semantics/forms/form-submission-0/form-double-submit-3.html.ini
new file mode 100644
index 00000000000..9f416703229
--- /dev/null
+++ b/tests/wpt/metadata/html/semantics/forms/form-submission-0/form-double-submit-3.html.ini
@@ -0,0 +1,4 @@
+[form-double-submit-3.html]
+  [<button> should have the same double-submit protection as <input type=submit>]
+    expected: FAIL
+
diff --git a/tests/wpt/metadata/html/semantics/forms/form-submission-0/form-double-submit.html.ini b/tests/wpt/metadata/html/semantics/forms/form-submission-0/form-double-submit.html.ini
new file mode 100644
index 00000000000..b193c33c2b6
--- /dev/null
+++ b/tests/wpt/metadata/html/semantics/forms/form-submission-0/form-double-submit.html.ini
@@ -0,0 +1,4 @@
+[form-double-submit.html]
+  [default submit action should supersede onclick submit()]
+    expected: FAIL
+
diff --git a/tests/wpt/metadata/html/webappapis/scripting/events/compile-event-handler-settings-objects.html.ini b/tests/wpt/metadata/html/webappapis/scripting/events/compile-event-handler-settings-objects.html.ini
index 0cef5158fae..01f7b72cbe7 100644
--- a/tests/wpt/metadata/html/webappapis/scripting/events/compile-event-handler-settings-objects.html.ini
+++ b/tests/wpt/metadata/html/webappapis/scripting/events/compile-event-handler-settings-objects.html.ini
@@ -4,3 +4,6 @@
   [The incumbent settings object while executing the compiled callback via Web IDL's invoke must be that of the node document]
     expected: TIMEOUT
 
+  [The entry settings object while executing the compiled callback via Web IDL's invoke must be that of the node document]
+    expected: FAIL
+
diff --git a/tests/wpt/metadata/resource-timing/iframe-failed-commit.html.ini b/tests/wpt/metadata/resource-timing/iframe-failed-commit.html.ini
new file mode 100644
index 00000000000..e02284faa14
--- /dev/null
+++ b/tests/wpt/metadata/resource-timing/iframe-failed-commit.html.ini
@@ -0,0 +1,22 @@
+[iframe-failed-commit.html]
+  [Precondition]
+    expected: FAIL
+
+  [Test iframe redirecting to non-existent host]
+    expected: FAIL
+
+  [Cross-origin iframe that doesn't comply with CSP attribute gets reported]
+    expected: FAIL
+
+  [Same-origin iframe that complies with CSP attribute gets reported]
+    expected: FAIL
+
+  [Cross-origin iframe that complies with CSP attribute gets reported]
+    expected: FAIL
+
+  [Same-origin iframe that doesn't comply with CSP attribute gets reported]
+    expected: FAIL
+
+  [Test iframe from non-existent host]
+    expected: FAIL
+
diff --git a/tests/wpt/metadata/webaudio/the-audio-api/the-audiobuffersourcenode-interface/sub-sample-buffer-stitching.html.ini b/tests/wpt/metadata/webaudio/the-audio-api/the-audiobuffersourcenode-interface/sub-sample-buffer-stitching.html.ini
index 810b01c377d..eaa21130cdc 100644
--- a/tests/wpt/metadata/webaudio/the-audio-api/the-audiobuffersourcenode-interface/sub-sample-buffer-stitching.html.ini
+++ b/tests/wpt/metadata/webaudio/the-audio-api/the-audiobuffersourcenode-interface/sub-sample-buffer-stitching.html.ini
@@ -602,3 +602,9 @@
   [X SNR (39.927354911150644 dB) is not greater than or equal to 65.737. Got 39.927354911150644.]
     expected: FAIL
 
+  [X SNR (-336.5274753602913 dB) is not greater than or equal to 65.737. Got -336.5274753602913.]
+    expected: FAIL
+
+  [X Stitched sine-wave buffers at sample rate 43800 does not equal [0,0.06264832615852356,0.12505052983760834,0.18696144223213196,0.24813786149024963,0.308339387178421,0.36732959747314453,0.4248766601085663,0.480754554271698,0.5347436666488647,0.5866320133209229,0.6362156271934509,0.6832997798919678,0.7276994585990906,0.7692402601242065,0.8077589869499207...\] with an element-wise tolerance of {"absoluteThreshold":0.0038986,"relativeThreshold":0}.\n\tIndex\tActual\t\t\tExpected\t\tAbsError\t\tRelError\t\tTest threshold\n\t[28696\]\t9.9558435935349637e+18\t9.3139332532882690e-1\t9.9558435935349637e+18\t1.0689193622919801e+19\t3.8985999999999999e-3\n\t[28697\]\t7.0477002859115601e-1\t9.0675884485244751e-1\t2.0198881626129150e-1\t2.2275913536212616e-1\t3.8985999999999999e-3\n\tMax AbsError of 9.9558435935349637e+18 at index of 28696.\n\tMax RelError of 1.0689193622919801e+19 at index of 28696.\n]
+    expected: FAIL
+
diff --git a/tests/wpt/metadata/webaudio/the-audio-api/the-audiocontext-interface/audiocontext-not-fully-active.html.ini b/tests/wpt/metadata/webaudio/the-audio-api/the-audiocontext-interface/audiocontext-not-fully-active.html.ini
index f1281b5ae81..b7e13cf7726 100644
--- a/tests/wpt/metadata/webaudio/the-audio-api/the-audiocontext-interface/audiocontext-not-fully-active.html.ini
+++ b/tests/wpt/metadata/webaudio/the-audio-api/the-audiocontext-interface/audiocontext-not-fully-active.html.ini
@@ -1,5 +1,4 @@
 [audiocontext-not-fully-active.html]
-  expected: TIMEOUT
   [frame in navigated remote-site frame]
     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 663a1f8fa30..00000000000
--- a/tests/wpt/metadata/webmessaging/with-ports/018.html.ini
+++ /dev/null
@@ -1,5 +0,0 @@
-[018.html]
-  expected: TIMEOUT
-  [origin of the script that invoked the method, javascript:]
-    expected: TIMEOUT
-
diff --git a/tests/wpt/metadata/workers/baseurl/alpha/sharedworker-in-worker.html.ini b/tests/wpt/metadata/workers/baseurl/alpha/sharedworker-in-worker.html.ini
index 333edb3a26e..650c91da4a6 100644
--- a/tests/wpt/metadata/workers/baseurl/alpha/sharedworker-in-worker.html.ini
+++ b/tests/wpt/metadata/workers/baseurl/alpha/sharedworker-in-worker.html.ini
@@ -1,4 +1,5 @@
 [sharedworker-in-worker.html]
+  expected: ERROR
   [Base URL in workers: new SharedWorker()]
     expected: FAIL
 
diff --git a/tests/wpt/metadata/workers/constructors/Worker/Worker-constructor.html.ini b/tests/wpt/metadata/workers/constructors/Worker/Worker-constructor.html.ini
deleted file mode 100644
index 80f9a4f15b8..00000000000
--- a/tests/wpt/metadata/workers/constructors/Worker/Worker-constructor.html.ini
+++ /dev/null
@@ -1,2 +0,0 @@
-[Worker-constructor.html]
-  expected: ERROR
diff --git a/tests/wpt/web-platform-tests/.github/workflows/detect_pull_request_preview.yml b/tests/wpt/web-platform-tests/.github/workflows/detect_pull_request_preview.yml
deleted file mode 100644
index 02870d8c7d2..00000000000
--- a/tests/wpt/web-platform-tests/.github/workflows/detect_pull_request_preview.yml
+++ /dev/null
@@ -1,25 +0,0 @@
-name: pr-preview-detect
-# This workflow triggers on deployment, which can never happen on a fork.
-on: deployment
-jobs:
-  detect-deployment:
-    runs-on: ubuntu-18.04
-    steps:
-    - uses: actions/checkout@v1
-      # By default, the "checkout" Action will attempt to check out the
-      # revision to be deployed. Because it does not fetch GitHub Pull Request
-      # branches, this will fail.
-      with:
-        ref: refs/heads/master
-    - name: Install dependency
-      run: pip install requests
-    - name: Detect deployment
-      run:
-        ./tools/ci/pr_preview.py
-          --host https://api.github.com
-          --github-project web-platform-tests/wpt
-          detect
-          --target https://wptpr.live
-          --timeout 600
-      env:
-        DEPLOY_TOKEN: ${{ secrets.DEPLOY_TOKEN }}
diff --git a/tests/wpt/web-platform-tests/.github/workflows/pull_request_previews.yml b/tests/wpt/web-platform-tests/.github/workflows/pull_request_previews.yml
index bf049dd9e63..676aff30212 100644
--- a/tests/wpt/web-platform-tests/.github/workflows/pull_request_previews.yml
+++ b/tests/wpt/web-platform-tests/.github/workflows/pull_request_previews.yml
@@ -1,31 +1,35 @@
-name: pr-preview-sync
+# Create previews for pull requests on https://wptpr.live
+#
+# Mirroring pull requests to wptpr.live requires write access to the WPT GitHub
+# repository. This means that we cannot run any code from the pull request in
+# doing so, to defend against attacks from malicious pull requests. As such,
+# this workflow uses the 'pull_request_target' event which runs in the context
+# of the base repository and thus doesn't run code from the pull request. Any
+# code run in this workflow should NOT checkout or trust code from the pull
+# request.
+#
+# Note that in pull_request_target the GITHUB token is read/write.
+name: create-pr-preview
 on:
-  schedule:
-    - cron: '*/5 * * * *'
+  pull_request_target:
+    types: [opened, synchronize, reopened, closed, labeled, unlabeled]
 jobs:
   update-pr-preview:
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v1
       with:
         fetch-depth: 1
     - name: Install dependency
       run: pip install requests
-    - name: Synchronize state
+    - name: Deploy PR
       # Use a conditional step instead of a conditional job to work around #20700.
       if: github.repository == 'web-platform-tests/wpt'
       run:
         ./tools/ci/pr_preview.py
           --host https://api.github.com
           --github-project web-platform-tests/wpt
-          synchronize
-          --window 480
+          --target https://wptpr.live
+          --timeout 600
       env:
-        # This Workflow must trigger further workflows. The GitHub-provided
-        # `GITHUB_TOKEN` secret is incapable of doing this [1], so a
-        # user-generated token must be specified instead. This token requires
-        # the "repo" scope, and is should be stored as a Secret named
-        # "DEPLOY_TOKEN" in this GitHub project.
-        #
-        # [1] https://help.github.com/en/github/automating-your-workflow-with-github-actions/events-that-trigger-workflows
-        DEPLOY_TOKEN: ${{ secrets.DEPLOY_TOKEN }}
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
diff --git a/tests/wpt/web-platform-tests/content-security-policy/script-src/script-src-1_10.html b/tests/wpt/web-platform-tests/content-security-policy/script-src/script-src-1_10.html
index a1bfdaeb15b..fa25976c128 100644
--- a/tests/wpt/web-platform-tests/content-security-policy/script-src/script-src-1_10.html
+++ b/tests/wpt/web-platform-tests/content-security-policy/script-src/script-src-1_10.html
@@ -15,7 +15,7 @@
         var t_spv = async_test("Test that securitypolicyviolation event is fired");
         
         window.addEventListener("securitypolicyviolation", t_spv.step_func_done(function(e) {
-            assert_equals(e.violatedDirective, "script-src");
+            assert_equals(e.violatedDirective, "script-src-elem");
         }));
     </script>
 
diff --git a/tests/wpt/web-platform-tests/css/css-animations/translation-animation-subpixel-offset-ref.html b/tests/wpt/web-platform-tests/css/css-animations/translation-animation-subpixel-offset-ref.html
new file mode 100644
index 00000000000..5fc04d972b4
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-animations/translation-animation-subpixel-offset-ref.html
@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<style>
+div {
+  position: absolute;
+  top: 11px;
+  left: 1px;
+  width: 100px;
+  height: 100px;
+  background: green;
+}
+</style>
+<div></div>
diff --git a/tests/wpt/web-platform-tests/css/css-animations/translation-animation-subpixel-offset.html b/tests/wpt/web-platform-tests/css/css-animations/translation-animation-subpixel-offset.html
new file mode 100644
index 00000000000..5692a082328
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-animations/translation-animation-subpixel-offset.html
@@ -0,0 +1,37 @@
+<!DOCTYPE html>
+<title>Translation-only transform animation with subpixel offset</title>
+<link rel="author" title="Xianzhu Wang" href="mailto:wangxianzhu@chromium.org">
+<link rel="help" href="https://crbug.com/1155029">
+<link rel="match" href="translation-animation-subpixel-offset-ref.html">
+<style>
+@keyframes move {
+  0% {transform: translateY(10px);}
+  100% {transform: translateY(10px);}
+}
+#red {
+  position: absolute;
+  top: 11px;
+  left: 1px;
+  width: 100px;
+  height: 100px;
+  background: red;
+}
+#container {
+  position: absolute;
+  top: 0.4px;
+  left: 0.6px;
+}
+#target {
+  position: relative;
+  top: 0.4px;
+  left: 0.6px;
+  width: 100px;
+  height: 100px;
+  background: green;
+  animation: move 1s infinite alternate;
+}
+</style>
+<div id="red"></div>
+<div id="container">
+  <div id="target"></div>
+</div>
diff --git a/tests/wpt/web-platform-tests/css/css-backgrounds/background-attachment-local/attachment-local-clipping-image-5.html b/tests/wpt/web-platform-tests/css/css-backgrounds/background-attachment-local/attachment-local-clipping-image-5.html
index ddd02dcfaef..1d6f1a8c662 100644
--- a/tests/wpt/web-platform-tests/css/css-backgrounds/background-attachment-local/attachment-local-clipping-image-5.html
+++ b/tests/wpt/web-platform-tests/css/css-backgrounds/background-attachment-local/attachment-local-clipping-image-5.html
@@ -2,7 +2,7 @@
 <title>CSS Test: background-{attachment: local; clip: padding-box; image}; border-radius</title>
 <link rel="match" href="attachment-local-clipping-image-4-ref.html" />
 <meta name="flags" content="dom" />
-<meta name=fuzzy content="0-10;0-160">
+<meta name=fuzzy content="0-10;0-300">
 <link rel="author" title="Simon Sapin" href="http://exyr.org/about/" />
 <link rel="help" href="http://www.w3.org/TR/css3-background/#the-background-attachment" />
 <style>
diff --git a/tests/wpt/web-platform-tests/css/css-contain/content-visibility/content-visibility-079-ref.html b/tests/wpt/web-platform-tests/css/css-contain/content-visibility/content-visibility-079-ref.html
new file mode 100644
index 00000000000..416f23e8ca6
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-contain/content-visibility/content-visibility-079-ref.html
@@ -0,0 +1,8 @@
+<!doctype HTML>
+<html>
+<meta charset="utf8">
+<title>CSS Content Visibility: auto in overflow hidden paints (reference)</title>
+<link rel="author" title="Vladimir Levin" href="mailto:vmpstr@chromium.org">
+<link rel="help" href="https://drafts.csswg.org/css-contain/#content-visibility">
+
+<div>content</div>
diff --git a/tests/wpt/web-platform-tests/css/css-contain/content-visibility/content-visibility-079.html b/tests/wpt/web-platform-tests/css/css-contain/content-visibility/content-visibility-079.html
new file mode 100644
index 00000000000..9a8b46bf5c6
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-contain/content-visibility/content-visibility-079.html
@@ -0,0 +1,16 @@
+<!doctype HTML>
+<meta charset="utf8">
+<title>CSS Content Visibility: auto in overflow hidden paints</title>
+<link rel="author" title="Vladimir Levin" href="mailto:vmpstr@chromium.org">
+<link rel="help" href="https://drafts.csswg.org/css-contain/#content-visibility">
+<link rel="match" href="content-visibility-079-ref.html">
+<meta name="assert" content="content-visibility auto element paints in an overflow hidden element that is not sized">
+
+<style>
+.auto { content-visibility: auto; }
+.overflow { overflow: hidden; }
+</style>
+
+<div class=overflow>
+  <div class=auto>content</div>
+</div>
diff --git a/tests/wpt/web-platform-tests/css/css-overflow/no-scrollable-overflow-vertical-rl-2.html b/tests/wpt/web-platform-tests/css/css-overflow/no-scrollable-overflow-vertical-rl-2.html
new file mode 100644
index 00000000000..895f9bafc62
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-overflow/no-scrollable-overflow-vertical-rl-2.html
@@ -0,0 +1,46 @@
+<!DOCTYPE html>
+<!-- Any copyright is dedicated to the Public Domain.
+     http://creativecommons.org/publicdomain/zero/1.0/ -->
+<html>
+  <meta charset="utf-8">
+  <title>CSS Overflow Test: Scrollable overflow area of a multicol container in vertical-rl writing-mode</title>
+  <link rel="author" title="Ting-Yu Lin" href="mailto:tlin@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="match" href="../reference/ref-filled-green-100px-square-only.html">
+  <meta name="assert" content="This test verifies the nested float element in a multicol container in vertical-rl writing-mode shouldn't contribute to its container'sscrollable overflow area.">
+
+  <style>
+  .scroll-container {
+    writing-mode: vertical-rl;
+    inline-size: 100px;
+    block-size: 100px;
+    overflow: auto;
+  }
+  .multicol {
+    block-size: 100px;
+    inline-size: 100px;
+    column-fill: auto;
+    column-count: 2;
+    column-gap: 0;
+  }
+  .float {
+    float: left;
+    inline-size: 50px;
+    block-size: 100px;
+    background: green;
+  }
+  </style>
+
+  <!--This test passes if the scroll-container has no scrollbar. -->
+
+  <p>Test passes if there is a filled green square.</p>
+  <div class="scroll-container">
+    <div class="multicol">
+      <div>
+        <div style="block-size: 100px; background: green;"></div>
+        <div class="float"></div>
+      </div>
+    </div>
+  </div>
+</html>
diff --git a/tests/wpt/web-platform-tests/css/css-overflow/no-scrollable-overflow-vertical-rl.html b/tests/wpt/web-platform-tests/css/css-overflow/no-scrollable-overflow-vertical-rl.html
new file mode 100644
index 00000000000..13385a2685c
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-overflow/no-scrollable-overflow-vertical-rl.html
@@ -0,0 +1,44 @@
+<!DOCTYPE html>
+<!-- Any copyright is dedicated to the Public Domain.
+     http://creativecommons.org/publicdomain/zero/1.0/ -->
+<html>
+  <meta charset="utf-8">
+  <title>CSS Overflow Test: Scrollable overflow area of a multicol container in vertical-rl writing-mode</title>
+  <link rel="author" title="Ting-Yu Lin" href="mailto:tlin@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="match" href="../reference/ref-filled-green-100px-square-only.html">
+  <meta name="assert" content="This test verifies the float element in a multicol container in vertical-rl writing-mode shouldn't contribute to its container'sscrollable overflow area.">
+
+  <style>
+  .scroll-container {
+    writing-mode: vertical-rl;
+    inline-size: 100px;
+    block-size: 100px;
+    overflow: auto;
+  }
+  .multicol {
+    block-size: 100px;
+    inline-size: 100px;
+    column-fill: auto;
+    column-count: 2;
+    column-gap: 0;
+  }
+  .float {
+    float: left;
+    inline-size: 50px;
+    block-size: 100px;
+    background: green;
+  }
+  </style>
+
+  <!--This test passes if the scroll-container has no scrollbar. -->
+
+  <p>Test passes if there is a filled green square.</p>
+  <div class="scroll-container">
+    <div class="multicol">
+      <div style="block-size: 100px; background: green;"></div>
+      <div class="float"></div>
+    </div>
+  </div>
+</html>
diff --git a/tests/wpt/web-platform-tests/css/css-tables/fixed-layout-2.html b/tests/wpt/web-platform-tests/css/css-tables/fixed-layout-2.html
index 7cb09d4dd04..13a4664249f 100644
--- a/tests/wpt/web-platform-tests/css/css-tables/fixed-layout-2.html
+++ b/tests/wpt/web-platform-tests/css/css-tables/fixed-layout-2.html
@@ -60,9 +60,9 @@
             100
         ],
         [
-            "Table-layout:fixed reports it is not applied when width is auto",
+            "Table-layout:fixed reports fixed when width is auto",
             getComputedStyle(document.querySelector("x-table:nth-of-type(1)")).tableLayout,
-            'auto'
+            'fixed'
         ],
         [
             "Table-layout:fixed is not applied when width is max-content",
@@ -70,9 +70,9 @@
             100
         ],
         [
-            "Table-layout:fixed reports it is not applied when width is max-content",
+            "Table-layout:fixed reports fixed when width is max-content",
             getComputedStyle(document.querySelector("x-table:nth-of-type(2)")).tableLayout,
-            'auto'
+            'fixed'
         ],
         [
             "Table-layout:fixed is not applied when width is min-content",
diff --git a/tests/wpt/web-platform-tests/docs/writing-tests/testdriver-extension-tutorial.md b/tests/wpt/web-platform-tests/docs/writing-tests/testdriver-extension-tutorial.md
index 0d73f9d41f8..185a27f1a46 100644
--- a/tests/wpt/web-platform-tests/docs/writing-tests/testdriver-extension-tutorial.md
+++ b/tests/wpt/web-platform-tests/docs/writing-tests/testdriver-extension-tutorial.md
@@ -15,6 +15,31 @@ First, we need to think of what the API will look like a little. We will be usin
 
 The first part of this will be browser agnostic, but later we will need to implement a specific layer for each browser (here we will do Firefox and Chrome).
 
+## RFC Process
+
+Before we invest any significant work into extending the testdriver.js API, we should check in with other stakeholders of the Web Platform Tests community on the proposed changes, by writing an [RFC](https://github.com/web-platform-tests/rfcs) ("request for comments"). This is especially useful for changes that may affect test authors or downstream users of web-platform-tests.
+
+The [process is given in more detail in the RFC repo](https://github.com/web-platform-tests/rfcs#the-rfc-process), but to start let's send in a PR to the RFCs repo by adding a file named `rfcs/testdriver_set_window_rect.md`:
+
+```md
+# RFC N: Add window resizing to testdriver.js
+(*Note: N should be replaced by the PR number*)
+
+## Summary
+
+Add testdriver.js support for the [Set Window Rect command](https://w3c.github.io/webdriver/#set-window-rect).
+
+## Details
+(*add details here*)
+
+## Risks
+(*add risks here*)
+```
+
+Members of the community will then have the opportunity to comment on our proposed changes, and perhaps suggest improvements to our ideas. If all goes well it will be approved and merged in.
+
+With that said, developing a prototype implementation may help others evaluate the proposal during the RFC process, so let's move on to writing some code.
+
 ## Code!
 
 ### [resources/testdriver.js](https://github.com/web-platform-tests/wpt/blob/master/resources/testdriver.js)
@@ -273,4 +298,3 @@ async_test(t => {
 });
 </script>
 ```
-
diff --git a/tests/wpt/web-platform-tests/html/browsers/sandboxing/resources/check-sandbox-flags.html b/tests/wpt/web-platform-tests/html/browsers/sandboxing/resources/check-sandbox-flags.html
new file mode 100644
index 00000000000..0dc95315f16
--- /dev/null
+++ b/tests/wpt/web-platform-tests/html/browsers/sandboxing/resources/check-sandbox-flags.html
@@ -0,0 +1,8 @@
+<script>
+  try {
+    document.domain = document.domain;
+    parent.postMessage('document-domain-is-allowed', '*');
+  } catch (error) {
+    parent.postMessage('document-domain-is-disallowed', '*');
+  }
+</script>
diff --git a/tests/wpt/web-platform-tests/html/browsers/sandboxing/sandbox-initial-empty-document-toward-same-origin.html b/tests/wpt/web-platform-tests/html/browsers/sandboxing/sandbox-initial-empty-document-toward-same-origin.html
new file mode 100644
index 00000000000..d1306c97032
--- /dev/null
+++ b/tests/wpt/web-platform-tests/html/browsers/sandboxing/sandbox-initial-empty-document-toward-same-origin.html
@@ -0,0 +1,30 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>
+  Check sandbox-flags inheritance in case of javascript window reuse.
+</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<body>
+<script>
+promise_test(async test => {
+  let message = new Promise(resolve =>
+    window.addEventListener("message", event => resolve(event.data))
+  );
+
+  // Create an initial empty document in the iframe, sandboxed. It will attempt
+  // to load a slow page, but won't have time.
+  let iframe = document.createElement("iframe");
+  iframe.setAttribute("sandbox", "allow-scripts allow-same-origin");
+  iframe.src = "/fetch/api/resources/infinite-slow-response.py";
+  document.body.appendChild(iframe);
+
+  // Remove sandbox flags. This should apply to documents committed from
+  // navigations started after this instruction.
+  iframe.removeAttribute("sandbox");
+  iframe.src = "./resources/check-sandbox-flags.html";
+
+  // The window is reused, but the new sandbox flags should be used.
+  assert_equals(await message, "document-domain-is-allowed");
+});
+</script>
diff --git a/tests/wpt/web-platform-tests/html/cross-origin-opener-policy/reporting/resources/redirect.py b/tests/wpt/web-platform-tests/html/cross-origin-opener-policy/reporting/resources/redirect.py
index 21a3dec9d22..88dbd60fae7 100644
--- a/tests/wpt/web-platform-tests/html/cross-origin-opener-policy/reporting/resources/redirect.py
+++ b/tests/wpt/web-platform-tests/html/cross-origin-opener-policy/reporting/resources/redirect.py
@@ -1,3 +1,5 @@
+from wptserve.utils import isomorphic_encode
+
 def main(request, response):
     response.status = 302
-    response.headers.set(b"Location", request.url[request.url.find('?')+1:])
+    response.headers.set(b"Location", isomorphic_encode(request.url[request.url.find(u'?')+1:]))
diff --git a/tests/wpt/web-platform-tests/html/cross-origin-opener-policy/reporting/resources/reporting-common.js b/tests/wpt/web-platform-tests/html/cross-origin-opener-policy/reporting/resources/reporting-common.js
index 3b1820cebb8..01f835e12ad 100644
--- a/tests/wpt/web-platform-tests/html/cross-origin-opener-policy/reporting/resources/reporting-common.js
+++ b/tests/wpt/web-platform-tests/html/cross-origin-opener-policy/reporting/resources/reporting-common.js
@@ -171,7 +171,8 @@ function navigationReportingTest(testName, host, coop, coep, coopRo, coepRo,
       `|header(Cross-Origin-Embedder-Policy-Report-Only,${encodeURIComponent(coepRo)})`+
       `&uuid=${executorToken}`;
       const openee = window.open(openee_url);
-      t.add_cleanup(() => send(5, "window.close()"));
+      const uuid = token();
+      t.add_cleanup(() => send(uuid, "window.close()"));
 
       // 1. Make sure the new document is loaded.
       send(executorToken, `
diff --git a/tests/wpt/web-platform-tests/html/rendering/non-replaced-elements/the-fieldset-and-legend-elements/fieldset-border-radius-with-alpha-ref.html b/tests/wpt/web-platform-tests/html/rendering/non-replaced-elements/the-fieldset-and-legend-elements/fieldset-border-radius-with-alpha-ref.html
index 577482a328b..5cfe13c40d4 100644
--- a/tests/wpt/web-platform-tests/html/rendering/non-replaced-elements/the-fieldset-and-legend-elements/fieldset-border-radius-with-alpha-ref.html
+++ b/tests/wpt/web-platform-tests/html/rendering/non-replaced-elements/the-fieldset-and-legend-elements/fieldset-border-radius-with-alpha-ref.html
@@ -2,10 +2,10 @@
 <style>
 div {
     background-color: green;
-    height: 150px;
+    height: 110px;
     position: absolute;
     width: 150px;
-    top: 50px;
+    top: 70px;
 }
 </style>
 <p>There should be no red.</p>
diff --git a/tests/wpt/web-platform-tests/html/rendering/non-replaced-elements/the-fieldset-and-legend-elements/fieldset-border-radius-with-alpha.html b/tests/wpt/web-platform-tests/html/rendering/non-replaced-elements/the-fieldset-and-legend-elements/fieldset-border-radius-with-alpha.html
index 36b9fc8c8ef..7a942076fbe 100644
--- a/tests/wpt/web-platform-tests/html/rendering/non-replaced-elements/the-fieldset-and-legend-elements/fieldset-border-radius-with-alpha.html
+++ b/tests/wpt/web-platform-tests/html/rendering/non-replaced-elements/the-fieldset-and-legend-elements/fieldset-border-radius-with-alpha.html
@@ -9,14 +9,18 @@ fieldset {
     height: 100px;
     width: 100px;
 }
+legend {
+    height: 50px;
+    width: 50px;
+}
 div {
     background-color: green;
-    height: 150px;
+    height: 110px;
     position: absolute;
     width: 150px;
-    top: 50px;
+    top: 70px;
 }
 </style>
 <p>There should be no red.</p>
-<fieldset></fieldset>
+<fieldset><legend></legend></fieldset>
 <div></div>
diff --git a/tests/wpt/web-platform-tests/input-events/input-events-cut-paste-manual.html b/tests/wpt/web-platform-tests/input-events/input-events-cut-paste-manual.html
deleted file mode 100644
index 4091c87cdd3..00000000000
--- a/tests/wpt/web-platform-tests/input-events/input-events-cut-paste-manual.html
+++ /dev/null
@@ -1,83 +0,0 @@
-<!DOCTYPE html>
-<meta charset="utf-8">
-<title>Cut and Paste should trigger corresponding InputEvent</title>
-<script src="/resources/testharness.js"></script>
-<script src="/resources/testharnessreport.js"></script>
-<p>To manually run this test, please follow the steps below:<br/>
-1. Select 'plain' => Cut (e.g. Ctrl/Cmd-X) => Paste (e.g. Ctrl/Cmd-V).<br/>
-2. Select 'rich' => Cut => Paste.<br/>
-3. Select 'prevent' => Paste.<br/>
-4. Select 'prevent' => Cut => Select 'normal' => Paste.<br/>
-<br/>
-If a "PASS" result appears the test passes, otherwise it fails</p>
-<textarea id="test1_plain">plain</textarea>
-<p id="test2_editable" contenteditable><b>rich</b></p>
-<p id="test3_editable_prevent" contenteditable>prevent</p>
-<p id="test3_editable_normal" contenteditable>normal</p>
-<script>
-async_test(t => {
-    const expectedEventLog = [
-        'cut-[null]', 'beforeinput-deleteByCut', 'input-deleteByCut',
-        'paste-[null]', 'beforeinput-insertFromPaste', 'input-insertFromPaste'];
-    const actualEventLog = [];
-
-    for (let eventType of ['beforeinput', 'input', 'cut', 'paste']) {
-        document.getElementById('test1_plain').addEventListener(eventType, t.step_func(event => {
-            if (event.type === 'beforeinput' && event.inputType === 'insertFromPaste') {
-                assert_equals(event.data, 'plain');
-                assert_equals(event.dataTransfer, null);
-            }
-
-            actualEventLog.push(`${event.type}-${event.inputType || '[null]'}`);
-            if (actualEventLog.length === expectedEventLog.length) {
-                assert_array_equals(actualEventLog, expectedEventLog,
-                    `Expected: ${expectedEventLog}; Actual: ${actualEventLog}.`);
-                t.done();
-            }
-        }));
-    }
-}, 'Event order and data on textarea.');
-
-async_test(t => {
-    const expectedEventLog = [
-        'cut-[null]', 'beforeinput-deleteByCut', 'input-deleteByCut',
-        'paste-[null]', 'beforeinput-insertFromPaste', 'input-insertFromPaste'];
-    const actualEventLog = [];
-
-    for (let eventType of ['beforeinput', 'input', 'cut', 'paste']) {
-        document.getElementById('test2_editable').addEventListener(eventType, t.step_func(event => {
-            if (event.type === 'beforeinput' && event.inputType === 'insertFromPaste') {
-                assert_equals(event.data, null);
-                assert_equals(event.dataTransfer.getData('text/plain'), 'rich');
-                assert_regexp_match(event.dataTransfer.getData('text/html'), /<b.*>rich<\/b>$/);
-            }
-
-            actualEventLog.push(`${event.type}-${event.inputType || '[null]'}`);
-            if (actualEventLog.length === expectedEventLog.length) {
-                assert_array_equals(actualEventLog, expectedEventLog,
-                    `Expected: ${expectedEventLog}; Actual: ${actualEventLog}.`);
-                t.done();
-            }
-        }));
-    }
-}, 'Event order and dataTransfer on contenteditable.');
-
-async_test(t => {
-    const prevent = document.getElementById('test3_editable_prevent');
-    const normal = document.getElementById('test3_editable_normal');
-    prevent.addEventListener('beforeinput', t.step_func(event => {
-        if (event.inputType === 'deleteByCut' ||
-            event.inputType === 'insertFromPaste') {
-            event.preventDefault();
-        }
-    }));
-
-    normal.addEventListener('input', t.step_func(event => {
-        if (event.inputType === 'insertFromPaste') {
-            assert_equals(prevent.textContent, 'prevent');
-            assert_equals(normal.textContent, 'prevent');
-            t.done();
-        }
-    }));
-}, 'preventDefault() should prevent DOM modification but allow clipboard updates.');
-</script>
diff --git a/tests/wpt/web-platform-tests/input-events/input-events-cut-paste.html b/tests/wpt/web-platform-tests/input-events/input-events-cut-paste.html
new file mode 100644
index 00000000000..f2ca5a0a654
--- /dev/null
+++ b/tests/wpt/web-platform-tests/input-events/input-events-cut-paste.html
@@ -0,0 +1,141 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Cut and Paste should trigger corresponding InputEvent</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script type="text/javascript" src="pointerevent_support.js"></script>
+<p>To manually run this test, please follow the steps below:<br/>
+1. Select 'plain' => Cut (e.g. Ctrl/Cmd-X) => Paste (e.g. Ctrl/Cmd-V).<br/>
+2. Select 'rich' => Cut => Paste.<br/>
+3. Select 'prevent' => Paste.<br/>
+4. Select 'prevent' => Cut => Select 'normal' => Paste.<br/>
+<br/>
+If a "PASS" result appears the test passes, otherwise it fails</p>
+<textarea id="test1_plain">plain</textarea>
+<p id="test2_editable" contenteditable><b>rich</b></p>
+<p id="test3_editable_prevent" contenteditable>prevent</p>
+<p id="test3_editable_normal" contenteditable>normal</p>
+<script>
+
+function resolveWhen(condition) {
+  return new Promise((resolve, reject) => {
+    function tick() {
+      if (condition())
+        resolve();
+      else
+        requestAnimationFrame(tick.bind(this));
+    }
+    tick();
+  });
+}
+
+let modifier_key = "\uE009";
+if(navigator.platform.includes('Mac'))
+    modifier_key = "\uE03D";
+const commands = {
+    COPY: 'copy',
+    CUT: 'cut',
+    PASTE: 'paste',
+}
+function selectTextCommand(target, command) {
+  let command_key = "";
+  if(command == "copy")
+    command_key = "c";
+  else if (command == "cut")
+    command_key = "x";
+  else if (command == "paste")
+    command_key = "v";
+  return new test_driver.Actions()
+      .pointerMove(0, 0, {origin: target})
+      .pointerDown()
+      .pointerUp()
+      .addTick()
+      .keyDown(modifier_key)
+      .keyDown("a")
+      .keyUp("a")
+      .keyDown(command_key)
+      .keyUp(command_key)
+      .keyUp(modifier_key)
+      .send();
+}
+
+function selectTextCutAndPaste(target1, target2) {
+  return selectTextCommand(target1, commands.CUT).then(() => {
+    return selectTextCommand(target2, commands.PASTE);
+  })
+}
+
+promise_test(async test => {
+  const expectedEventLog = [
+        'cut-[null]', 'beforeinput-deleteByCut', 'input-deleteByCut',
+        'paste-[null]', 'beforeinput-insertFromPaste', 'input-insertFromPaste'];
+  const actualEventLog = [];
+  const text1 = document.getElementById("test1_plain");
+
+  for (let eventType of ['beforeinput', 'input', 'cut', 'paste']) {
+      text1.addEventListener(eventType, test.step_func(function() {
+          if (event.type === 'beforeinput' && event.inputType === 'insertFromPaste') {
+              assert_equals(event.data, 'plain');
+              assert_equals(event.dataTransfer, null);
+          }
+
+          actualEventLog.push(`${event.type}-${event.inputType || '[null]'}`);
+      }));
+  }
+  await selectTextCutAndPaste(text1, text1);
+  await resolveWhen(() => { return actualEventLog.length == expectedEventLog.length });
+  assert_array_equals(actualEventLog, expectedEventLog,
+                      `Expected: ${expectedEventLog}; Actual: ${actualEventLog}.`);
+}, 'Event order and data on textarea.');
+
+promise_test(async test => {
+    const expectedEventLog = [
+        'cut-[null]', 'beforeinput-deleteByCut', 'input-deleteByCut',
+        'paste-[null]', 'beforeinput-insertFromPaste', 'input-insertFromPaste'];
+    const actualEventLog = [];
+    const text2 = document.getElementById("test2_editable");
+
+    for (let eventType of ['beforeinput', 'input', 'cut', 'paste']) {
+        text2.addEventListener(eventType, test.step_func(function() {
+            if (event.type === 'beforeinput' && event.inputType === 'insertFromPaste') {
+                assert_equals(event.data, null);
+                assert_equals(event.dataTransfer.getData('text/plain'), 'rich');
+                assert_regexp_match(event.dataTransfer.getData('text/html'), /<b.*>rich<\/b>$/);
+            }
+
+            actualEventLog.push(`${event.type}-${event.inputType || '[null]'}`);
+        }));
+    }
+    await selectTextCutAndPaste(text2, text2);
+    await resolveWhen(() => { return actualEventLog.length == expectedEventLog.length });
+    assert_array_equals(actualEventLog, expectedEventLog,
+                        `Expected: ${expectedEventLog}; Actual: ${actualEventLog}.`);
+}, 'Event order and dataTransfer on contenteditable.');
+
+promise_test(async test => {
+    const prevent = document.getElementById('test3_editable_prevent');
+    const normal = document.getElementById('test3_editable_normal');
+    prevent.addEventListener('beforeinput', test.step_func(function() {
+        if (event.inputType === 'deleteByCut' ||
+            event.inputType === 'insertFromPaste') {
+            event.preventDefault();
+        }
+    }));
+
+    normal.addEventListener('input', test.step_func(function() {
+        if (event.inputType === 'insertFromPaste') {
+            assert_equals(prevent.textContent, 'prevent');
+            assert_equals(normal.textContent, 'prevent');
+        }
+    }));
+
+    await selectTextCommand(prevent, commands.PASTE);
+    await selectTextCutAndPaste(prevent, normal);
+    await resolveWhen(() => { return normal.textContent == 'prevent' });
+    assert_equals(prevent.textContent, 'prevent');
+    assert_equals(normal.textContent, 'prevent');
+}, 'preventDefault() should prevent DOM modification but allow clipboard updates.');
+</script>
diff --git a/tests/wpt/web-platform-tests/js-self-profiling/__dir__.headers b/tests/wpt/web-platform-tests/js-self-profiling/__dir__.headers
index 63b60e490f4..35b10bd2ccd 100644
--- a/tests/wpt/web-platform-tests/js-self-profiling/__dir__.headers
+++ b/tests/wpt/web-platform-tests/js-self-profiling/__dir__.headers
@@ -1,2 +1,3 @@
 Cross-Origin-Opener-Policy: same-origin
 Cross-Origin-Embedder-Policy: require-corp
+Document-Policy: js-profiling
diff --git a/tests/wpt/web-platform-tests/media-source/mse-for-webcodecs/tentative/mediasource-webcodecs-addsourcebuffer.html b/tests/wpt/web-platform-tests/media-source/mse-for-webcodecs/tentative/mediasource-webcodecs-addsourcebuffer.html
new file mode 100644
index 00000000000..a9dd7072b07
--- /dev/null
+++ b/tests/wpt/web-platform-tests/media-source/mse-for-webcodecs/tentative/mediasource-webcodecs-addsourcebuffer.html
@@ -0,0 +1,207 @@
+<!DOCTYPE html>
+<html>
+  <title>Test MediaSource addSourceBuffer overloads for WebCodecs Audio/VideoDecoderConfigs</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+
+setup(() => {
+  assert_implements(
+      SourceBuffer.prototype.hasOwnProperty('appendEncodedChunks'),
+      'SourceBuffer prototype hasOwnProperty "appendEncodedChunks", used ' +
+          'here to feature detect MSE-for-WebCodecs implementation.');
+});
+
+testInvalidArguments();
+testValidArguments();
+
+function getValidAudioConfig() {
+  // TODO(crbug.com/1144908): Consider confirming with WebCodecs'
+  // isConfigSupported() once that API is available.
+  return {
+    codec: 'opus',
+    sampleRate: 48000,
+    numberOfChannels: 2
+  };
+}
+
+function getValidVideoConfig() {
+  // TODO(crbug.com/1144908): Consider confirming with WebCodecs'
+  // isConfigSupported() once that API is available.
+  return { codec: 'vp09.00.10.08' };
+}
+
+function testInvalidArguments() {
+  const INVALID_CASES = [
+    { arg: null,
+      name: 'null' },
+    { arg: undefined,
+      name: 'undefined' },
+    { arg: { },
+      name: '{ empty dictionary }' },
+    {
+      arg: {
+        audioConfig: getValidAudioConfig(),
+        videoConfig: getValidVideoConfig()
+      },
+      name: '{ valid audioConfig and videoConfig }',
+    },
+    {
+      arg: {
+        audioConfig: {
+          codec: 'bogus',
+          sampleRate: 48000,
+          numberOfChannels: 2
+        }
+      },
+      name: 'bad audio config codec',
+    },
+    { arg: { videoConfig: { codec: 'bogus' } },
+      name: 'bad video config codec' },
+    { arg: { audioConfig: { sampleRate: 48000, numberOfChannels: 2 } },
+      name: 'audio config missing required member "codec"' },
+    { arg: { videoConfig: { } },
+      name: 'video config missing required member "codec"' },
+  ];
+
+  [ 'closed', 'open', 'ended' ].forEach(readyStateScenario => {
+    INVALID_CASES.forEach(invalidCase => {
+      runAddSourceBufferTest(invalidCase['arg'] /* argument */,
+          false /* isValidArgument */,
+          invalidCase['name'] /* argumentDescription */,
+          readyStateScenario);
+    });
+  });
+}
+
+function testValidArguments() {
+  const VALID_CASES = [
+    {
+      arg: {
+        audioConfig: getValidAudioConfig()
+      },
+      name: 'valid audioConfig'
+    },
+    {
+      arg: {
+        videoConfig: getValidVideoConfig()
+      },
+      name: 'valid videoConfig'
+    },
+  ];
+
+  [ 'closed', 'open', 'ended' ].forEach(readyStateScenario => {
+    VALID_CASES.forEach(validCase => {
+      runAddSourceBufferTest(
+          validCase['arg'] /* argument */,
+          true /* isValidArgument */,
+          validCase['name'] /* argumentDescription */,
+          readyStateScenario);
+    });
+  });
+}
+
+async function getClosedMediaSource(test) {
+  let mediaSource = new MediaSource();
+  assert_equals(mediaSource.readyState, 'closed');
+  return mediaSource;
+}
+
+async function getOpenMediaSource(test) {
+  return new Promise(async resolve => {
+    const v = document.createElement('video');
+    const mediaSource = new MediaSource();
+    const url = URL.createObjectURL(mediaSource);
+    mediaSource.addEventListener('sourceopen', test.step_func(() => {
+      URL.revokeObjectURL(url);
+      assert_equals(mediaSource.readyState, 'open', 'MediaSource is open');
+      resolve(mediaSource);
+    }), { once: true });
+    v.src = url;
+  });
+}
+
+async function getEndedMediaSource(test) {
+  let mediaSource = await getOpenMediaSource(test);
+  assert_equals(mediaSource.readyState, 'open', 'MediaSource is open');
+  mediaSource.endOfStream();
+  assert_equals(mediaSource.readyState, 'ended', 'MediaSource is ended');
+  return mediaSource;
+}
+
+function runAddSourceBufferTest(argument, isValidArgument, argumentDescription, readyStateScenario) {
+  const testDescription = 'addSourceBuffer call with ' +
+      (isValidArgument ? 'valid' : 'invalid') +
+      ' argument ' + argumentDescription + ' while MediaSource readyState is ' +
+      readyStateScenario;
+
+  switch(readyStateScenario) {
+    case 'closed':
+      promise_test(async t => {
+        let mediaSource = await getClosedMediaSource(t);
+        assert_equals(mediaSource.readyState, 'closed');
+        let sourceBuffer;
+        if (isValidArgument) {
+          assert_throws_dom('InvalidStateError',
+              () => { sourceBuffer = mediaSource.addSourceBuffer(argument); },
+              'addSourceBuffer(valid config) throws InvalidStateError if MediaSource is "closed"');
+          assert_equals(sourceBuffer, undefined,
+              'addSourceBuffer result for valid config while "closed" should be exception');
+        } else {
+          assert_throws_js(TypeError,
+              () => { sourceBuffer = mediaSource.addSourceBuffer(argument); },
+              'addSourceBuffer(invalid config) throws TypeError if MediaSource is "closed"');
+          assert_equals(sourceBuffer, undefined,
+              'addSourceBuffer result for invalid config while "closed" should be exception');
+        }
+      }, testDescription);
+      break;
+    case 'open':
+      promise_test(async t => {
+        let mediaSource = await getOpenMediaSource(t);
+        assert_equals(mediaSource.readyState, 'open', 'MediaSource is open');
+        let sourceBuffer;
+        if (isValidArgument) {
+          // TODO(crbug.com/1144908): Update to expect success once the impl is
+          // more complete.
+          assert_throws_dom('QuotaExceededError',
+            () => { sourceBuffer = mediaSource.addSourceBuffer(argument); },
+            'addSourceBuffer(valid config) throws QuotaExceededError');
+          assert_equals(sourceBuffer, undefined,
+            'addSourceBuffer result for valid config while "open" should be exception');
+        } else {
+          assert_throws_js(TypeError,
+            () => { sourceBuffer = mediaSource.addSourceBuffer(argument); },
+            'addSourceBuffer(invalid config) throws TypeError if MediaSource is "open"');
+          assert_equals(sourceBuffer, undefined,
+            'addSourceBufferResult for invalid config while "open" should be exception');
+        }
+      }, testDescription);
+      break;
+    case 'ended':
+      promise_test(async t => {
+        let mediaSource = await getEndedMediaSource(t);
+        let sourceBuffer;
+        if (isValidArgument) {
+          assert_throws_dom('InvalidStateError',
+              () => { sourceBuffer = mediaSource.addSourceBuffer(argument); },
+              'addSourceBuffer(valid config) throws InvalidStateError if MediaSource is "ended"');
+          assert_equals(sourceBuffer, undefined,
+              'addSourceBuffer result for valid config while "ended" should be exception');
+        } else {
+          assert_throws_js(TypeError,
+              () => { sourceBuffer = mediaSource.addSourceBuffer(argument); },
+              'addSourceBuffer(invalid config) throws TypeError if MediaSource is "ended"');
+          assert_equals(sourceBuffer, undefined,
+              'addSourceBuffer result for invalid config while "ended" should be exception');
+        }
+      }, testDescription);
+      break;
+    default:
+      assert_unreached('Invalid readyStateScenario ' + readyStateScenario);
+      break;
+  }
+}
+
+</script>
+</html>
diff --git a/tests/wpt/web-platform-tests/resource-timing/iframe-failed-commit.html b/tests/wpt/web-platform-tests/resource-timing/iframe-failed-commit.html
new file mode 100644
index 00000000000..75e19f788ef
--- /dev/null
+++ b/tests/wpt/web-platform-tests/resource-timing/iframe-failed-commit.html
@@ -0,0 +1,69 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8" />
+<title>Resource Timing - test that unsuccessful iframes create entries</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<body>
+<script>
+test(() => {
+  const entries = performance.getEntriesByType("resource");
+  assert_equals(entries.length, 3, "Precondition - Entries for blocking scripts fired");
+}, "Precondition");
+
+const run_test = async (t, url, csp) => {
+  const setPerformanceObserver = new Promise(resolve => {
+    const po = new PerformanceObserver(resolve);
+    po.observe({type: "resource"});
+  });
+  const timeout = new Promise(resolve => t.step_timeout(resolve, 1000));
+  const frame = document.createElement("iframe");
+  frame.src = url;
+  if (csp) {
+    frame.csp = csp;
+  }
+  document.body.appendChild(frame);
+  const list = await Promise.race([setPerformanceObserver, timeout]);
+  assert_equals(typeof(list), "object", "No iframe entry was fired");
+  const entries = list.getEntriesByName(url);
+  assert_equals(entries.length, 1);
+}
+
+const {REMOTE_ORIGIN, ORIGINAL_HOST, HTTPS_PORT} = get_host_info();
+const nonexistent_url = "https://nonexistent." + ORIGINAL_HOST + ":" + HTTPS_PORT + "/";
+
+promise_test(t => {
+  return run_test(t, nonexistent_url);
+}, "Test iframe from non-existent host");
+
+promise_test(t => {
+  const url = new URL("resources/fake_responses.py?redirect=" + nonexistent_url, location.href);
+  return run_test(t, url.toString());
+}, "Test iframe redirecting to non-existent host");
+
+const csp_directive = "default-src 'none'";
+promise_test(t => {
+  const url = new URL("/resource-timing/resources/csp-default-none.html", location.href);
+  return run_test(t, url, csp_directive);
+}, "Same-origin iframe that complies with CSP attribute gets reported");
+
+promise_test(t => {
+  const url = new URL("/resource-timing/resources/green_frame.htm", location.href);
+  return run_test(t, url.toString(), csp_directive);
+}, "Same-origin iframe that doesn't comply with CSP attribute gets reported");
+
+promise_test(t => {
+  const url = new URL("/resource-timing/resources/csp-default-none.html", REMOTE_ORIGIN);
+  return run_test(t, url.toString(), csp_directive);
+}, "Cross-origin iframe that complies with CSP attribute gets reported");
+
+promise_test(t => {
+  const url = new URL("/resource-timing/resources/green_frame.htm", REMOTE_ORIGIN);
+  return run_test(t, url.toString(), csp_directive);
+}, "Cross-origin iframe that doesn't comply with CSP attribute gets reported");
+
+</script>
+</body>
+</html>
diff --git a/tests/wpt/web-platform-tests/resource-timing/resources/csp-default-none.html b/tests/wpt/web-platform-tests/resource-timing/resources/csp-default-none.html
new file mode 100644
index 00000000000..1f59d8c2250
--- /dev/null
+++ b/tests/wpt/web-platform-tests/resource-timing/resources/csp-default-none.html
@@ -0,0 +1,3 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>empty page</title>
diff --git a/tests/wpt/web-platform-tests/resource-timing/resources/csp-default-none.html.headers b/tests/wpt/web-platform-tests/resource-timing/resources/csp-default-none.html.headers
new file mode 100644
index 00000000000..d66f886dd23
--- /dev/null
+++ b/tests/wpt/web-platform-tests/resource-timing/resources/csp-default-none.html.headers
@@ -0,0 +1,2 @@
+Content-Security-Policy: default-src 'none'
+
diff --git a/tests/wpt/web-platform-tests/tools/ci/pr_preview.py b/tests/wpt/web-platform-tests/tools/ci/pr_preview.py
index 2396e9b8aee..5bd2365164b 100755
--- a/tests/wpt/web-platform-tests/tools/ci/pr_preview.py
+++ b/tests/wpt/web-platform-tests/tools/ci/pr_preview.py
@@ -25,7 +25,7 @@ API_RATE_LIMIT_THRESHOLD = 0.2
 LABEL = 'safe for preview'
 # The number of seconds to wait between attempts to verify that a submission
 # preview is available on the Pull Request preview server
-POLLING_PERIOD = 5
+POLLING_PERIOD = 15
 # Pull Requests from authors with the following associations to the project
 # should automatically receive previews
 #
@@ -44,7 +44,7 @@ logging.basicConfig(level=logging.INFO)
 logger = logging.getLogger(__name__)
 
 def gh_request(method_name, url, body=None, media_type=None):
-    github_token = os.environ['DEPLOY_TOKEN']
+    github_token = os.environ['GITHUB_TOKEN']
 
     kwargs = {
         'headers': {
@@ -67,6 +67,9 @@ def gh_request(method_name, url, body=None, media_type=None):
 
     return resp.json()
 
+class GitHubRateLimitException(Exception):
+    pass
+
 def guard(resource):
     '''Decorate a `Project` instance method which interacts with the GitHub
     API, ensuring that the subsequent request will not deplete the relevant
@@ -90,7 +93,7 @@ def guard(resource):
             )
 
             if limit and float(remaining) / limit < API_RATE_LIMIT_THRESHOLD:
-                raise Exception(
+                raise GitHubRateLimitException(
                     'Exiting to avoid GitHub.com API request throttling.'
                 )
 
@@ -132,25 +135,6 @@ class Project(object):
 
         return {pr['number']: pr for pr in data['items']}
 
-    def pull_request_is_from_fork(self, pull_request):
-        pr_number = pull_request['number']
-        logger.info('Checking if pull request %s is from a fork', pr_number)
-
-        # We may already have this information; if so no need to make another
-        # API call.
-        if 'head' not in pull_request:
-            pull_request = self.get_pull_request(pr_number)
-
-        repo_name = pull_request['head']['repo']['full_name']
-        is_fork = repo_name != self._github_project
-
-        logger.info(
-            'Pull request %s is from \'%s\'. Is a fork: %s',
-            pr_number, repo_name, is_fork
-        )
-
-        return is_fork
-
     @guard('core')
     def create_ref(self, refspec, revision):
         url = '{}/repos/{}/git/refs'.format(self._host, self._github_project)
@@ -206,7 +190,7 @@ class Project(object):
         return deployments.pop() if len(deployments) else None
 
     @guard('core')
-    def update_deployment(self, target, deployment, state, description=''):
+    def add_deployment_status(self, target, deployment, state, description=''):
         if state in ('pending', 'success'):
             pr_number = deployment['environment'][len(DEPLOYMENT_PREFIX):]
             environment_url = '{}/{}'.format(target, pr_number)
@@ -227,7 +211,7 @@ class Remote(object):
         # The repository in the GitHub Actions environment is configured with
         # a remote whose URL uses unauthenticated HTTPS, making it unsuitable
         # for pushing changes.
-        self._token = os.environ['DEPLOY_TOKEN']
+        self._token = os.environ['GITHUB_TOKEN']
 
     def _git(self, command):
         return subprocess.check_output([
@@ -306,131 +290,130 @@ def should_be_mirrored(project, pull_request):
                 pull_request['user']['login'] not in AUTOMATION_GITHUB_USERS and
                 pull_request['author_association'] in TRUSTED_AUTHOR_ASSOCIATIONS
             )
-        ) and
-        # Query this last as it requires another API call to verify
-        not project.pull_request_is_from_fork(pull_request)
+        )
     )
 
 def is_deployed(host, deployment):
     worktree_name = deployment['environment'][len(DEPLOYMENT_PREFIX):]
-    response = requests.get(
-        '{}/.git/worktrees/{}/HEAD'.format(host, worktree_name)
-    )
+    url = '{}/.git/worktrees/{}/HEAD'.format(host, worktree_name)
+    logger.info('Issuing request: GET %s', url)
+    response = requests.get(url)
 
+    logger.info('Response status code: %s', response.status_code)
     if response.status_code != 200:
         return False
 
+    logger.info('Response text: %s', response.text.strip())
     return response.text.strip() == deployment['sha']
 
-def synchronize(host, github_project, window):
-    '''Inspect all Pull Requests which have been modified in a given window of
-    time. Add or remove the "preview" label and update or delete the relevant
-    git refs according to the status of each Pull Request.'''
+def update_mirror_refs(project, remote, pull_request):
+    '''Update the WPT refs that control mirroring of this pull request.
 
-    project = Project(host, github_project)
-    remote = Remote(github_project)
+    Two sets of refs are used to control wptpr.live's mirroring of pull
+    requests:
 
-    pull_requests = project.get_pull_requests(
-        time.gmtime(time.time() - window)
+        1. refs/prs-trusted-for-preview/{number}
+        2. refs/prs-open/{number}
+
+    wptpr.live will only mirror a pull request if both exist for the given pull
+    request number; otherwise the pull request is either not open or is not
+    trustworthy (e.g. came from someone who doesn't have push access anyway.)
+
+    This method returns the revision that is being mirrored, or None if the
+    pull request should not be mirrored.
+    '''
+
+    refspec_trusted = 'prs-trusted-for-preview/{number}'.format(
+        **pull_request
     )
+    refspec_open = 'prs-open/{number}'.format(**pull_request)
+    revision_latest = remote.get_revision(
+        'pull/{number}/head'.format(**pull_request)
+    )
+    revision_trusted = remote.get_revision(refspec_trusted)
+    revision_open = remote.get_revision(refspec_open)
 
-    # It is possible we may miss some pull requests if this script breaks or is
-    # not run for a while and the PR falls outside the checked window. To
-    # ensure that closed pull requests are deleted, extend the list of pull
-    # requests to look at with any that have an existing refs/prs-open/{pr} ref
-    # in the repo.
-    existing_pr_numbers = remote.get_pull_requests_with_open_ref()
-    for pr_number in existing_pr_numbers:
-        if pr_number in pull_requests:
-            continue
-        pull_request = project.get_pull_request(pr_number)
-        pull_requests[pull_request['number']] = pull_request
+    if should_be_mirrored(project, pull_request):
+        logger.info('Pull Request should be mirrored')
 
-    for pull_request in pull_requests.values():
-        logger.info('Processing Pull Request #%(number)d', pull_request)
+        if revision_trusted is None:
+            project.create_ref(refspec_trusted, revision_latest)
+        elif revision_trusted != revision_latest:
+            project.update_ref(refspec_trusted, revision_latest)
 
-        refspec_trusted = 'prs-trusted-for-preview/{number}'.format(
-            **pull_request
-        )
-        refspec_open = 'prs-open/{number}'.format(**pull_request)
-        revision_latest = remote.get_revision(
-            'pull/{number}/head'.format(**pull_request)
-        )
-        revision_trusted = remote.get_revision(refspec_trusted)
-        revision_open = remote.get_revision(refspec_open)
+        if revision_open is None:
+            project.create_ref(refspec_open, revision_latest)
+        elif revision_open != revision_latest:
+            project.update_ref(refspec_open, revision_latest)
 
-        if should_be_mirrored(project, pull_request):
-            logger.info('Pull Request should be mirrored')
+        return revision_latest
 
-            if revision_trusted is None:
-                project.create_ref(refspec_trusted, revision_latest)
-            elif revision_trusted != revision_latest:
-                project.update_ref(refspec_trusted, revision_latest)
+    logger.info('Pull Request should not be mirrored')
 
-            if revision_open is None:
-                project.create_ref(refspec_open, revision_latest)
-            elif revision_open != revision_latest:
-                project.update_ref(refspec_open, revision_latest)
+    if not has_mirroring_label(pull_request) and revision_trusted is not None:
+        remote.delete_ref(refspec_trusted)
 
-            if project.get_deployment(revision_latest) is None:
-                project.create_deployment(
-                    pull_request, revision_latest
-                )
-        else:
-            logger.info('Pull Request should not be mirrored')
+    if revision_open is not None and not is_open(pull_request):
+        remote.delete_ref(refspec_open)
 
-            if not has_mirroring_label(pull_request) and revision_trusted is not None:
-                remote.delete_ref(refspec_trusted)
+    # No revision to be deployed to wptpr.live
+    return None
 
-            if revision_open is not None and not is_open(pull_request):
-                remote.delete_ref(refspec_open)
+class DeploymentFailedException(Exception):
+    pass
 
-def detect(host, github_project, target, timeout):
-    '''Manage the status of a GitHub Deployment by polling the Pull Request
-    preview website until the Deployment is complete or a timeout is
-    reached.'''
+def deploy(project, target, pull_request, revision, timeout):
+    '''Create a GitHub deployment for the given pull request and revision.
 
-    project = Project(host, github_project)
-
-    with open(os.environ['GITHUB_EVENT_PATH']) as handle:
-        data = json.loads(handle.read())
-
-    logger.info('Event data: %s', json.dumps(data, indent=2))
-
-    deployment = data['deployment']
-
-    if not deployment['environment'].startswith(DEPLOYMENT_PREFIX):
-        logger.info(
-            'Deployment environment "%s" is unrecognized. Exiting.',
-            deployment['environment']
-        )
+    This method creates a pending GitHub deployment, waits for the
+    corresponding revision to be available on wptpr.live and marks the
+    deployment as successful. If the revision does not appear in the given
+    timeout, the deployment is marked as errored instead.'''
+    if project.get_deployment(revision) is not None:
         return
 
+    deployment = project.create_deployment(pull_request, revision)
+
     message = 'Waiting up to {} seconds for Deployment {} to be available on {}'.format(
         timeout, deployment['environment'], target
     )
     logger.info(message)
-    project.update_deployment(target, deployment, 'pending', message)
+    project.add_deployment_status(target, deployment, 'pending', message)
 
     start = time.time()
-
     while not is_deployed(target, deployment):
         if time.time() - start > timeout:
             message = 'Deployment did not become available after {} seconds'.format(timeout)
-            project.update_deployment(target, deployment, 'error', message)
-            raise Exception(message)
+            project.add_deployment_status(target, deployment, 'error', message)
+            raise DeploymentFailedException(message)
 
         time.sleep(POLLING_PERIOD)
 
-    result = project.update_deployment(target, deployment, 'success')
+    result = project.add_deployment_status(target, deployment, 'success')
     logger.info(json.dumps(result, indent=2))
 
+def main(host, github_project, target, timeout):
+    project = Project(host, github_project)
+    remote = Remote(github_project)
+
+    with open(os.environ['GITHUB_EVENT_PATH']) as handle:
+        data = json.load(handle)
+
+    logger.info('Event data: %s', json.dumps(data, indent=2))
+
+    pull_request = data['pull_request']
+
+    logger.info('Processing Pull Request #%(number)d', pull_request)
+
+    revision_to_mirror = update_mirror_refs(project, remote, pull_request)
+    if revision_to_mirror:
+        deploy(project, target, pull_request, revision_to_mirror, timeout)
+
 if __name__ == '__main__':
     parser = argparse.ArgumentParser(
-        description='''Synchronize the state of a GitHub.com project with the
-            underlying git repository in order to support a externally-hosted
-            Pull Request preview system. Communicate the state of that system
-            via GitHub Deployments associated with each Pull Request.'''
+        description='''Mirror a pull request to an externally-hosted preview
+            system, and create a GitHub Deployment associated with the pull
+            request pointing at the preview.'''
     )
     parser.add_argument(
         '--host', required=True, help='the location of the GitHub API server'
@@ -441,36 +424,19 @@ if __name__ == '__main__':
         help='''the GitHub organization and GitHub project name, separated by
             a forward slash (e.g. "web-platform-tests/wpt")'''
     )
-    subparsers = parser.add_subparsers(title='subcommands')
-
-    parser_sync = subparsers.add_parser(
-        'synchronize', help=synchronize.__doc__
-    )
-    parser_sync.add_argument(
-        '--window',
-        type=int,
-        required=True,
-        help='''the number of seconds prior to the current moment within which
-            to search for GitHub Pull Requests. Any Pull Requests updated in
-            this time frame will be considered for synchronization.'''
-    )
-    parser_sync.set_defaults(func=synchronize)
-
-    parser_detect = subparsers.add_parser('detect', help=detect.__doc__)
-    parser_detect.add_argument(
+    parser.add_argument(
         '--target',
         required=True,
         help='''the URL of the website to which submission previews are
             expected to become available'''
     )
-    parser_detect.add_argument(
+    parser.add_argument(
         '--timeout',
         type=int,
         required=True,
         help='''the number of seconds to wait for a submission preview to
             become available before reporting a GitHub Deployment failure'''
     )
-    parser_detect.set_defaults(func=detect)
 
     values = dict(vars(parser.parse_args()))
-    values.pop('func')(**values)
+    main(**values)
diff --git a/tests/wpt/web-platform-tests/tools/ci/tests/test_pr_preview.py b/tests/wpt/web-platform-tests/tools/ci/tests/test_pr_preview.py
index ed6310c1ea1..87478727d3e 100644
--- a/tests/wpt/web-platform-tests/tools/ci/tests/test_pr_preview.py
+++ b/tests/wpt/web-platform-tests/tools/ci/tests/test_pr_preview.py
@@ -14,10 +14,11 @@ import sys
 import tempfile
 import threading
 
-subject = os.path.join(
-    os.path.dirname(os.path.abspath(__file__)), '..', 'pr_preview.py'
-)
-test_host = 'localhost'
+sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '..')))
+import pr_preview
+
+
+TEST_HOST = 'localhost'
 
 
 def same_members(a, b):
@@ -81,7 +82,10 @@ class MockHandler(BaseHTTPRequestHandler, object):
         self.server.actual_traffic.append((request, response))
         self.send_response(response[0])
         self.end_headers()
-        self.wfile.write(json.dumps(response[1]).encode('utf-8'))
+        if self.server.reponse_body_is_json:
+            self.wfile.write(json.dumps(response[1]).encode('utf-8'))
+        else:
+            self.wfile.write(response[1].encode('utf-8'))
 
     def do_DELETE(self):
         return self.do_all()
@@ -100,10 +104,11 @@ class MockServer(HTTPServer, object):
     '''HTTP server that responds to all requests with status code 200 and body
     '{}' unless an alternative status code and body are specified for the given
     method and path in the `responses` parameter.'''
-    def __init__(self, address, expected_traffic):
+    def __init__(self, address, expected_traffic, reponse_body_is_json=True):
         super(MockServer, self).__init__(address, MockHandler)
         self.expected_traffic = expected_traffic
         self.actual_traffic = []
+        self.reponse_body_is_json = reponse_body_is_json
 
     def __enter__(self):
         threading.Thread(target=lambda: self.serve_forever()).start()
@@ -115,21 +120,19 @@ class MockServer(HTTPServer, object):
 
 class Requests(object):
     get_rate = ('GET', '/rate_limit', {})
-    search = ('GET', '/search/issues', {})
-    pr_details = ('GET', '/repos/test-org/test-repo/pulls/23', {})
     ref_create_open = (
-        'POST', '/repos/test-org/test-repo/git/refs', {'ref':'refs/prs-open/23'}
+        'POST', '/repos/test-org/test-repo/git/refs', {'ref':'refs/prs-open/45'}
     )
     ref_create_trusted = (
         'POST',
         '/repos/test-org/test-repo/git/refs',
-        {'ref':'refs/prs-trusted-for-preview/23'}
+        {'ref':'refs/prs-trusted-for-preview/45'}
     )
     ref_update_open = (
-        'PATCH', '/repos/test-org/test-repo/git/refs/prs-open/23', {}
+        'PATCH', '/repos/test-org/test-repo/git/refs/prs-open/45', {}
     )
     ref_update_trusted = (
-        'PATCH', '/repos/test-org/test-repo/git/refs/prs-trusted-for-preview/23', {}
+        'PATCH', '/repos/test-org/test-repo/git/refs/prs-trusted-for-preview/45', {}
     )
     deployment_get = ('GET', '/repos/test-org/test-repo/deployments', {})
     deployment_create = ('POST', '/repos/test-org/test-repo/deployments', {})
@@ -167,9 +170,13 @@ class Responses(object):
 
 
 @contextlib.contextmanager
-def temp_repo():
+def temp_repo(change_dir=False):
+    original_dir = os.getcwd()
     directory = tempfile.mkdtemp()
 
+    if change_dir:
+        os.chdir(directory)
+
     try:
         subprocess.check_call(['git', 'init'], cwd=directory)
         # Explicitly create the default branch.
@@ -192,20 +199,22 @@ def temp_repo():
 
         yield directory
     finally:
+        if change_dir:
+            os.chdir(original_dir)
+
         shutil.rmtree(
             directory, ignore_errors=False, onerror=handle_remove_readonly
         )
 
-def synchronize(expected_traffic, refs={}):
-    env = {
-        'DEPLOY_TOKEN': 'c0ffee'
-    }
-    env.update(os.environ)
-    server = MockServer((test_host, 0), expected_traffic)
-    test_port = server.server_address[1]
+def update_mirror_refs(pull_request, expected_traffic, refs={}):
+    os.environ['GITHUB_TOKEN'] = 'c0ffee'
+
+    github_server = MockServer((TEST_HOST, 0), expected_traffic)
+    github_port = github_server.server_address[1]
     remote_refs = {}
 
-    with temp_repo() as local_repo, temp_repo() as remote_repo, server:
+    method_threw = False
+    with temp_repo(change_dir=True), temp_repo() as remote_repo, github_server:
         subprocess.check_call(
             ['git', 'commit', '--allow-empty', '-m', 'first'],
             cwd=remote_repo
@@ -214,9 +223,7 @@ def synchronize(expected_traffic, refs={}):
             ['git', 'commit', '--allow-empty', '-m', 'second'],
             cwd=remote_repo
         )
-        subprocess.check_call(
-            ['git', 'remote', 'add', 'origin', remote_repo], cwd=local_repo
-        )
+        subprocess.check_call(['git', 'remote', 'add', 'origin', remote_repo])
 
         for name, value in refs.items():
             subprocess.check_call(
@@ -224,26 +231,18 @@ def synchronize(expected_traffic, refs={}):
                 cwd=remote_repo
             )
 
-        child = subprocess.Popen(
-            [
-                sys.executable,
-                subject,
-                '--host',
-                'http://{}:{}'.format(test_host, test_port),
-                '--github-project',
-                'test-org/test-repo',
-                'synchronize',
-                '--window',
-                '3000'
-            ],
-            cwd=local_repo,
-            env=env
+        subprocess.check_call(['git', 'remote', '-v'])
+        project = pr_preview.Project(
+            'http://{}:{}'.format(TEST_HOST, github_port),
+            'test-org/test-repo',
         )
+        remote = pr_preview.Remote('test-org/test-repo')
+        try:
+            pr_preview.update_mirror_refs(project, remote, pull_request)
+        except pr_preview.GitHubRateLimitException:
+            method_threw = True
 
-        child.communicate()
-        lines = subprocess.check_output(
-            ['git', 'ls-remote', 'origin'], cwd=local_repo
-        )
+        lines = subprocess.check_output(['git', 'ls-remote', 'origin'])
         for line in lines.decode('utf-8').strip().split('\n'):
             revision, ref = line.split()
 
@@ -252,75 +251,55 @@ def synchronize(expected_traffic, refs={}):
 
             remote_refs[ref] = revision
 
-    return child.returncode, server.actual_traffic, remote_refs
+    return (
+        method_threw,
+        github_server.actual_traffic,
+        remote_refs,
+    )
 
 
-def detect(event, expected_github_traffic, expected_preview_traffic):
-    env = {
-        'DEPLOY_TOKEN': 'c0ffee'
-    }
-    env.update(os.environ)
-    github_server = MockServer((test_host, 0), expected_github_traffic)
+def deploy(pr_num, revision, expected_github_traffic, expected_preview_traffic):
+    os.environ['GITHUB_TOKEN'] = 'c0ffee'
+
+    github_server = MockServer((TEST_HOST, 0), expected_github_traffic)
     github_port = github_server.server_address[1]
-    preview_server = MockServer((test_host, 0), expected_preview_traffic)
+    preview_server = MockServer((TEST_HOST, 0), expected_preview_traffic, reponse_body_is_json=False)
     preview_port = preview_server.server_address[1]
 
-    with temp_repo() as repo, github_server, preview_server:
-        env['GITHUB_EVENT_PATH'] = repo + '/event.json'
-
-        with open(env['GITHUB_EVENT_PATH'], 'w') as handle:
-            handle.write(json.dumps(event))
-
-        child = subprocess.Popen(
-            [
-                sys.executable,
-                subject,
-                '--host',
-                'http://{}:{}'.format(test_host, github_port),
-                '--github-project',
-                'test-org/test-repo',
-                'detect',
-                '--target',
-                'http://{}:{}'.format(test_host, preview_port),
-                '--timeout',
-                '1'
-            ],
-            cwd=repo,
-            env=env
+    method_threw = False
+    with github_server, preview_server:
+        project = pr_preview.Project(
+            'http://{}:{}'.format(TEST_HOST, github_port),
+            'test-org/test-repo',
         )
-        child.communicate()
+        target = 'http://{}:{}'.format(TEST_HOST, preview_port)
+        pull_request = {'number': pr_num}
+        timeout = 1
+        try:
+            pr_preview.deploy(project, target, pull_request, revision, timeout)
+        except (pr_preview.GitHubRateLimitException, pr_preview.DeploymentFailedException):
+            method_threw = True
 
     return (
-        child.returncode,
+        method_threw,
         github_server.actual_traffic,
         preview_server.actual_traffic
     )
 
-
-def test_synchronize_zero_results():
-    expected_traffic = [
-        (Requests.get_rate, Responses.no_limit),
-        (Requests.search, (
-            200,
-            {
-                'items': [],
-                'incomplete_results': False
-            }
-        ))
-    ]
-
-    returncode, actual_traffic, remote_refs = synchronize(expected_traffic)
-
-    assert returncode == 0
-    assert same_members(expected_traffic, actual_traffic)
-
-def test_synchronize_fail_search_throttled():
+def test_update_mirror_refs_fail_rate_limited():
+    pull_request = {
+        'number': 45,
+        'labels': [],
+        'user': {'login': 'stephenmcgruer'},
+        'author_association': 'COLLABORATOR',
+        'closed_at': None,
+    }
     expected_traffic = [
         (Requests.get_rate, (
             200,
             {
                 'resources': {
-                    'search': {
+                    'core': {
                         'remaining': 1,
                         'limit': 10
                     }
@@ -329,451 +308,213 @@ def test_synchronize_fail_search_throttled():
         ))
     ]
 
-    returncode, actual_traffic, remote_refs = synchronize(expected_traffic)
+    method_threw, actual_traffic, remote_refs = update_mirror_refs(
+        pull_request, expected_traffic
+    )
 
-    assert returncode != 0
-    assert same_members(expected_traffic, actual_traffic)
-
-def test_synchronize_fail_incomplete_results():
-    expected_traffic = [
-        (Requests.get_rate, Responses.no_limit),
-        (Requests.search, (
-            200,
-            {
-                'items': [],
-                'incomplete_results': True
-            }
-        ))
-    ]
-
-    returncode, actual_traffic, remove_refs = synchronize(expected_traffic)
-
-    assert returncode != 0
+    assert method_threw
     assert same_members(expected_traffic, actual_traffic)
 
 def test_synchronize_ignore_closed():
-    expected_traffic = [
-        (Requests.get_rate, Responses.no_limit),
-        (Requests.search, (
-            200,
-            {
-                'items': [
-                    {
-                        'number': 23,
-                        'labels': [],
-                        'closed_at': '2019-10-28',
-                        'user': {'login': 'grace'},
-                        'author_association': 'COLLABORATOR'
-                    }
-                ],
-                'incomplete_results': False
-            }
-        ))
-    ]
+    # No existing refs, but a closed PR event comes in. Nothing should happen.
+    pull_request = {
+        'number': 45,
+        'labels': [],
+        'user': {'login': 'stephenmcgruer'},
+        'author_association': 'COLLABORATOR',
+        'closed_at': '2019-10-28',
+    }
+    expected_traffic = []
 
-    returncode, actual_traffic, remote_refs = synchronize(expected_traffic)
+    method_threw, actual_traffic, remote_refs = update_mirror_refs(
+        pull_request, expected_traffic
+    )
 
-    assert returncode == 0
+    assert not method_threw
     assert same_members(expected_traffic, actual_traffic)
 
-def test_synchronize_sync_collaborator():
+def test_update_mirror_refs_collaborator():
+    pull_request = {
+        'number': 45,
+        'labels': [],
+        'user': {'login': 'stephenmcgruer'},
+        'author_association': 'COLLABORATOR',
+        'closed_at': None,
+    }
     expected_traffic = [
         (Requests.get_rate, Responses.no_limit),
         (Requests.get_rate, Responses.no_limit),
-        (Requests.get_rate, Responses.no_limit),
-        (Requests.get_rate, Responses.no_limit),
-        (Requests.get_rate, Responses.no_limit),
-        (Requests.get_rate, Responses.no_limit),
-        (Requests.search, (
-            200,
-            {
-                'items': [
-                    {
-                        'number': 23,
-                        'labels': [],
-                        'closed_at': None,
-                        'user': {'login': 'grace'},
-                        'author_association': 'COLLABORATOR'
-                    }
-                ],
-                'incomplete_results': False
-            }
-        )),
-        (Requests.pr_details, (200,
-            {
-                'head': {
-                    'repo': {
-                        'full_name': 'test-org/test-repo'
-                    }
-                }
-            }
-        )),
         (Requests.ref_create_open, (200, {})),
         (Requests.ref_create_trusted, (200, {})),
-        (Requests.deployment_get, (200, {})),
-        (Requests.deployment_create, (200, {}))
     ]
 
-    returncode, actual_traffic, remote_refs = synchronize(expected_traffic)
+    method_threw, actual_traffic, remote_refs = update_mirror_refs(
+        pull_request, expected_traffic
+    )
 
-    assert returncode == 0
+    assert not method_threw
     assert same_members(expected_traffic, actual_traffic)
 
-def test_synchronize_ignore_collaborator_bot():
-    expected_traffic = [
-        (Requests.get_rate, Responses.no_limit),
-        (Requests.search, (
-            200,
-            {
-                'items': [
-                    {
-                        'number': 23,
-                        'labels': [],
-                        'closed_at': None,
-                        'user': {'login': 'chromium-wpt-export-bot'},
-                        'author_association': 'COLLABORATOR'
-                    }
-                ],
-                'incomplete_results': False
-            }
-        ))
-    ]
+def test_update_mirror_refs_ignore_collaborator_bot():
+    pull_request = {
+        'number': 45,
+        'labels': [],
+        'user': {'login': 'chromium-wpt-export-bot'},
+        'author_association': 'COLLABORATOR',
+        'closed_at': None,
+    }
+    expected_traffic = []
 
-    returncode, actual_traffic, remote_refs = synchronize(expected_traffic)
+    method_threw, actual_traffic, remote_refs = update_mirror_refs(
+        pull_request, expected_traffic
+    )
 
-    assert returncode == 0
+    assert not method_threw
     assert same_members(expected_traffic, actual_traffic)
 
-def test_synchronize_ignore_untrusted_contributor():
-    expected_traffic = [
-        (Requests.get_rate, Responses.no_limit),
-        (Requests.search, (
-            200,
-            {
-                'items': [
-                    {
-                        'number': 23,
-                        'labels': [],
-                        'closed_at': None,
-                        'user': {'login': 'grace'},
-                        'author_association': 'CONTRIBUTOR'
-                    }
-                ],
-                'incomplete_results': False
-            }
-        ))
-    ]
+def test_update_mirror_refs_ignore_untrusted_contributor():
+    pull_request = {
+        'number': 45,
+        'labels': [],
+        'user': {'login': 'stephenmcgruer'},
+        'author_association': 'CONTRIBUTOR',
+        'closed_at': None,
+    }
+    expected_traffic = []
 
-    returncode, actual_traffic, remote_refs = synchronize(expected_traffic)
+    method_threw, actual_traffic, remote_refs = update_mirror_refs(
+        pull_request, expected_traffic
+    )
 
-    assert returncode == 0
+    assert not method_threw
     assert same_members(expected_traffic, actual_traffic)
 
-def test_synchronize_ignore_pull_request_from_fork():
+def test_update_mirror_refs_trusted_contributor():
+    pull_request = {
+        'number': 45,
+        # user here is a contributor (untrusted), but the issue
+        # has been labelled as safe.
+        'labels': [{'name': 'safe for preview'}],
+        'user': {'login': 'Hexcles'},
+        'author_association': 'CONTRIBUTOR',
+        'closed_at': None,
+    }
     expected_traffic = [
         (Requests.get_rate, Responses.no_limit),
         (Requests.get_rate, Responses.no_limit),
-        (Requests.search, (
-            200,
-            {
-                'items': [
-                    {
-                        'number': 23,
-                        'labels': [],
-                        'closed_at': None,
-                        'user': {'login': 'grace'},
-                        'author_association': 'COLLABORATOR'
-                    }
-                ],
-                'incomplete_results': False
-            }
-        )),
-        (Requests.pr_details, (200,
-            {
-                'head': {
-                    'repo': {
-                        'full_name': 'some-other-org/test-repo'
-                    }
-                }
-            }
-        )),
-    ]
-
-    returncode, actual_traffic, remote_refs = synchronize(expected_traffic)
-
-    assert returncode == 0
-    assert same_members(expected_traffic, actual_traffic)
-
-def test_synchronize_sync_trusted_contributor():
-    expected_traffic = [
-        (Requests.get_rate, Responses.no_limit),
-        (Requests.get_rate, Responses.no_limit),
-        (Requests.get_rate, Responses.no_limit),
-        (Requests.get_rate, Responses.no_limit),
-        (Requests.get_rate, Responses.no_limit),
-        (Requests.get_rate, Responses.no_limit),
-        (Requests.search, (
-            200,
-            {
-                'items': [
-                    {
-                        'number': 23,
-                        # user here is a contributor (untrusted), but the issue
-                        # has been labelled as safe.
-                        'labels': [{'name': 'safe for preview'}],
-                        'closed_at': None,
-                        'user': {'login': 'Hexcles'},
-                        'author_association': 'CONTRIBUTOR'
-                    }
-                ],
-                'incomplete_results': False
-            }
-        )),
-        (Requests.pr_details, (200,
-            {
-                'head': {
-                    'repo': {
-                        'full_name': 'test-org/test-repo'
-                    }
-                }
-            }
-        )),
         (Requests.ref_create_open, (200, {})),
         (Requests.ref_create_trusted, (200, {})),
-        (Requests.deployment_get, (200, [])),
-        (Requests.deployment_create, (200, {}))
     ]
 
-    returncode, actual_traffic, remote_refs = synchronize(expected_traffic)
+    method_threw, actual_traffic, remote_refs = update_mirror_refs(
+        pull_request, expected_traffic
+    )
 
-    assert returncode == 0
+    assert not method_threw
     assert same_members(expected_traffic, actual_traffic)
 
 def test_synchronize_sync_bot_with_label():
+    pull_request = {
+        'number': 45,
+        # user here is a bot which is normally not mirrored,
+        # but the issue has been labelled as safe.
+        'labels': [{'name': 'safe for preview'}],
+        'user': {'login': 'chromium-wpt-export-bot'},
+        'author_association': 'COLLABORATOR',
+        'closed_at': None,
+    }
     expected_traffic = [
         (Requests.get_rate, Responses.no_limit),
         (Requests.get_rate, Responses.no_limit),
-        (Requests.get_rate, Responses.no_limit),
-        (Requests.get_rate, Responses.no_limit),
-        (Requests.get_rate, Responses.no_limit),
-        (Requests.get_rate, Responses.no_limit),
-        (Requests.search, (
-            200,
-            {
-                'items': [
-                    {
-                        'number': 23,
-                        # user here is a bot which is normally not mirrored,
-                        # but the issue has been labelled as safe.
-                        'labels': [{'name': 'safe for preview'}],
-                        'closed_at': None,
-                        'user': {'login': 'chromium-wpt-export-bot'},
-                        'author_association': 'COLLABORATOR'
-                    }
-                ],
-                'incomplete_results': False
-            }
-        )),
-        (Requests.pr_details, (200,
-            {
-                'head': {
-                    'repo': {
-                        'full_name': 'test-org/test-repo'
-                    }
-                }
-            }
-        )),
         (Requests.ref_create_open, (200, {})),
         (Requests.ref_create_trusted, (200, {})),
-        (Requests.deployment_get, (200, [])),
-        (Requests.deployment_create, (200, {}))
     ]
 
-    returncode, actual_traffic, remote_refs = synchronize(expected_traffic)
+    method_threw, actual_traffic, remote_refs = update_mirror_refs(
+        pull_request, expected_traffic
+    )
 
-    assert returncode == 0
+    assert not method_threw
     assert same_members(expected_traffic, actual_traffic)
 
-def test_synchronize_update_collaborator():
+def test_update_mirror_refs_update_collaborator():
+    pull_request = {
+        'number': 45,
+        'labels': [],
+        'user': {'login': 'stephenmcgruer'},
+        'author_association': 'COLLABORATOR',
+        'closed_at': None,
+    }
     expected_traffic = [
         (Requests.get_rate, Responses.no_limit),
         (Requests.get_rate, Responses.no_limit),
-        (Requests.get_rate, Responses.no_limit),
-        (Requests.get_rate, Responses.no_limit),
-        (Requests.get_rate, Responses.no_limit),
-        (Requests.get_rate, Responses.no_limit),
-        (Requests.search, (200,
-            {
-                'items': [
-                    {
-                        'number': 23,
-                        'labels': [],
-                        'closed_at': None,
-                        'user': {'login': 'grace'},
-                        'author_association': 'COLLABORATOR'
-                    }
-                ],
-                'incomplete_results': False
-            }
-        )),
-        (Requests.pr_details, (200,
-            {
-                'head': {
-                    'repo': {
-                        'full_name': 'test-org/test-repo'
-                    }
-                }
-            }
-        )),
-        (Requests.deployment_get, (200, [])),
         (Requests.ref_update_open, (200, {})),
         (Requests.ref_update_trusted, (200, {})),
-        (Requests.deployment_create, (200, {}))
     ]
     refs = {
-        'refs/pull/23/head': 'HEAD',
-        'refs/prs-open/23': 'HEAD~',
-        'refs/prs-trusted-for-preview/23': 'HEAD~'
+        'refs/pull/45/head': 'HEAD',
+        'refs/prs-open/45': 'HEAD~',
+        'refs/prs-trusted-for-preview/45': 'HEAD~'
     }
 
-    returncode, actual_traffic, remote_refs = synchronize(expected_traffic, refs)
+    method_threw, actual_traffic, remote_refs = update_mirror_refs(
+        pull_request, expected_traffic, refs
+    )
 
-    assert returncode == 0
+    assert not method_threw
     assert same_members(expected_traffic, actual_traffic)
 
 def test_synchronize_update_member():
+    pull_request = {
+        'number': 45,
+        'labels': [],
+        'user': {'login': 'jgraham'},
+        'author_association': 'MEMBER',
+        'closed_at': None,
+    }
     expected_traffic = [
         (Requests.get_rate, Responses.no_limit),
         (Requests.get_rate, Responses.no_limit),
-        (Requests.get_rate, Responses.no_limit),
-        (Requests.get_rate, Responses.no_limit),
-        (Requests.get_rate, Responses.no_limit),
-        (Requests.search, (200,
-            {
-                'items': [
-                    {
-                        'number': 23,
-                        'labels': [],
-                        'closed_at': None,
-                        'user': {'login': 'grace'},
-                        'author_association': 'MEMBER'
-                    }
-                ],
-                'incomplete_results': False
-            }
-        )),
-        (Requests.pr_details, (200,
-            {
-                'head': {
-                    'repo': {
-                        'full_name': 'test-org/test-repo'
-                    }
-                }
-            }
-        )),
-        (Requests.deployment_get, (200, [{'some': 'deployment'}])),
         (Requests.ref_update_open, (200, {})),
         (Requests.ref_update_trusted, (200, {}))
     ]
     refs = {
-        'refs/pull/23/head': 'HEAD',
-        'refs/prs-open/23': 'HEAD~',
-        'refs/prs-trusted-for-preview/23': 'HEAD~'
+        'refs/pull/45/head': 'HEAD',
+        'refs/prs-open/45': 'HEAD~',
+        'refs/prs-trusted-for-preview/45': 'HEAD~'
     }
 
-    returncode, actual_traffic, remote_refs = synchronize(expected_traffic, refs)
-
-    assert returncode == 0
-    assert same_members(expected_traffic, actual_traffic)
-
-def test_synchronize_delete_collaborator():
-    expected_traffic = [
-        (Requests.get_rate, Responses.no_limit),
-        (Requests.search, (200,
-            {
-                'items': [
-                    {
-                        'number': 23,
-                        'labels': [],
-                        'closed_at': '2019-10-30',
-                        'user': {'login': 'grace'},
-                        'author_association': 'COLLABORATOR'
-                    }
-                ],
-                'incomplete_results': False
-            }
-        ))
-    ]
-    refs = {
-        'refs/pull/23/head': 'HEAD',
-        'refs/prs-open/23': 'HEAD~',
-        'refs/prs-trusted-for-preview/23': 'HEAD~'
-    }
-
-    returncode, actual_traffic, remote_refs = synchronize(expected_traffic, refs)
-
-    assert returncode == 0
-    assert same_members(expected_traffic, actual_traffic)
-    assert list(remote_refs) == ['refs/pull/23/head']
-
-
-def test_synchronize_delete_old_pr():
-    # No pull requests from the search, but one outstanding closed PR.
-    expected_traffic = [
-        (Requests.get_rate, Responses.no_limit),
-        (Requests.get_rate, Responses.no_limit),
-        (Requests.search, (200,
-            {
-                'items': [],
-                'incomplete_results': False
-            }
-        )),
-        (Requests.pr_details, (200,
-            {
-                'number': 23,
-                'labels': [],
-                'closed_at': '2019-10-28',
-                'head': {
-                    'repo': {
-                        'full_name': 'test-org/test-repo'
-                    }
-                }
-            }
-        )),
-    ]
-    refs = {
-        'refs/pull/23/head': 'HEAD',
-        'refs/prs-open/23': 'HEAD~',
-        'refs/prs-trusted-for-preview/23': 'HEAD~'
-    }
-
-    returncode, actual_traffic, remote_refs = synchronize(expected_traffic, refs)
-
-    assert returncode == 0
-    assert same_members(expected_traffic, actual_traffic)
-    assert list(remote_refs) == ['refs/pull/23/head']
-
-
-def test_detect_ignore_unknown_env():
-    expected_github_traffic = []
-    expected_preview_traffic = []
-    event = {
-        'deployment': {
-            'id': 24601,
-            'environment': 'ghosts',
-            'sha': '3232'
-        }
-    }
-
-    returncode, actual_github_traffic, actual_preview_traffic = detect(
-        event, expected_github_traffic, expected_preview_traffic
+    method_threw, actual_traffic, remote_refs = update_mirror_refs(
+        pull_request, expected_traffic, refs
     )
 
-    assert returncode == 0
-    assert len(actual_github_traffic) == 0
-    assert len(actual_preview_traffic) == 0
+    assert not method_threw
+    assert same_members(expected_traffic, actual_traffic)
 
-def test_detect_fail_search_throttled():
+def test_update_mirror_refs_delete_collaborator():
+    pull_request = {
+        'number': 45,
+        'labels': [],
+        'user': {'login': 'stephenmcgruer'},
+        'author_association': 'COLLABORATOR',
+        'closed_at': 2019-10-30,
+    }
+    expected_traffic = []
+    refs = {
+        'refs/pull/45/head': 'HEAD',
+        'refs/prs-open/45': 'HEAD~',
+        'refs/prs-trusted-for-preview/45': 'HEAD~'
+    }
+
+    method_threw, actual_traffic, remote_refs = update_mirror_refs(
+        pull_request, expected_traffic, refs
+    )
+
+    assert not method_threw
+    assert same_members(expected_traffic, actual_traffic)
+    assert list(remote_refs) == ['refs/pull/45/head']
+
+def test_deploy_fail_rate_limited():
     expected_github_traffic = [
         (Requests.get_rate, (
             200,
@@ -788,99 +529,107 @@ def test_detect_fail_search_throttled():
         ))
     ]
     expected_preview_traffic = []
-    event = {
-        'deployment': {
-            'id': 24601,
-            'environment': 'wpt-preview-45',
-            'sha': '3232'
-        }
-    }
 
-    returncode, actual_github_traffic, actual_preview_traffic = detect(
-        event, expected_github_traffic, expected_preview_traffic
+    pr_num = 45
+    revision = "abcdef123"
+    method_threw, actual_github_traffic, actual_preview_traffic = deploy(
+        pr_num, revision, expected_github_traffic, expected_preview_traffic
     )
 
-    assert returncode == 1
+    assert method_threw
     assert actual_github_traffic == expected_github_traffic
     assert actual_preview_traffic == expected_preview_traffic
 
-def test_detect_success():
+def test_deploy_success():
+    pr_num = 45
+    revision = 'abcdef123'
+
     expected_github_traffic = [
+        (Requests.get_rate, Responses.no_limit),
+        (Requests.deployment_get, (200, [])),
+        (Requests.get_rate, Responses.no_limit),
+        (Requests.deployment_create, (200, {
+            'id': 24601,
+            'sha': revision,
+            'environment': 'wpt-preview-45',
+        })),
         (Requests.get_rate, Responses.no_limit),
         (Requests.deployment_status_create_pending, (200, {})),
         (Requests.get_rate, Responses.no_limit),
         (Requests.deployment_status_create_success, (200, {}))
     ]
     expected_preview_traffic = [
-        (Requests.preview, (200, 3232))
+        (Requests.preview, (200, revision))
     ]
-    event = {
-        'deployment': {
-            'id': 24601,
-            'environment': 'wpt-preview-45',
-            'sha': '3232'
-        }
-    }
 
-    returncode, actual_github_traffic, actual_preview_traffic = detect(
-        event, expected_github_traffic, expected_preview_traffic
+    method_threw, actual_github_traffic, actual_preview_traffic = deploy(
+        pr_num, revision, expected_github_traffic, expected_preview_traffic
     )
 
-    assert returncode == 0
+    assert not method_threw
     assert actual_github_traffic == expected_github_traffic
     assert actual_preview_traffic == expected_preview_traffic
 
-def test_detect_timeout_missing():
+def test_deploy_timeout_missing():
+    pr_num = 45
+    revision = 'abcdef123'
+
     expected_github_traffic = [
+        (Requests.get_rate, Responses.no_limit),
+        (Requests.deployment_get, (200, [])),
+        (Requests.get_rate, Responses.no_limit),
+        (Requests.deployment_create, (200, {
+            'id': 24601,
+            'sha': revision,
+            'environment': 'wpt-preview-45',
+        })),
         (Requests.get_rate, Responses.no_limit),
         (Requests.deployment_status_create_pending, (200, {})),
         (Requests.get_rate, Responses.no_limit),
         (Requests.deployment_status_create_error, (200, {}))
     ]
     expected_preview_traffic = [
-        (Requests.preview, (404, {}))
+        (Requests.preview, (404, ""))
     ]
-    event = {
-        'deployment': {
-            'id': 24601,
-            'environment': 'wpt-preview-45',
-            'sha': '3232'
-        }
-    }
 
-    returncode, actual_github_traffic, actual_preview_traffic = detect(
-        event, expected_github_traffic, expected_preview_traffic
+    method_threw, actual_github_traffic, actual_preview_traffic = deploy(
+        pr_num, revision, expected_github_traffic, expected_preview_traffic
     )
 
-    assert returncode == 1
+    assert method_threw
     assert expected_github_traffic == actual_github_traffic
     ping_count = len(actual_preview_traffic)
     assert ping_count > 0
     assert actual_preview_traffic == expected_preview_traffic * ping_count
 
-def test_detect_timeout_wrong_revision():
+def test_deploy_timeout_wrong_revision():
+    pr_num = 45
+    revision = 'abcdef123'
+
     expected_github_traffic = [
+        (Requests.get_rate, Responses.no_limit),
+        (Requests.deployment_get, (200, [])),
+        (Requests.get_rate, Responses.no_limit),
+        (Requests.deployment_create, (200, {
+            'id': 24601,
+            'sha': revision,
+            'environment': 'wpt-preview-45',
+        })),
         (Requests.get_rate, Responses.no_limit),
         (Requests.deployment_status_create_pending, (200, {})),
         (Requests.get_rate, Responses.no_limit),
         (Requests.deployment_status_create_error, (200, {}))
     ]
     expected_preview_traffic = [
-        (Requests.preview, (200, 1234))
+        # wptpr.live has the wrong revision deployed
+        (Requests.preview, (200, 'ghijkl456'))
     ]
-    event = {
-        'deployment': {
-            'id': 24601,
-            'environment': 'wpt-preview-45',
-            'sha': '3232'
-        }
-    }
 
-    returncode, actual_github_traffic, actual_preview_traffic = detect(
-        event, expected_github_traffic, expected_preview_traffic
+    method_threw, actual_github_traffic, actual_preview_traffic = deploy(
+        pr_num, revision, expected_github_traffic, expected_preview_traffic
     )
 
-    assert returncode == 1
+    assert method_threw
     assert expected_github_traffic == actual_github_traffic
     ping_count = len(actual_preview_traffic)
     assert ping_count > 0
diff --git a/tests/wpt/web-platform-tests/trusted-types/block-string-assignment-to-DOMWindowTimers-setTimeout-setInterval.tentative.html b/tests/wpt/web-platform-tests/trusted-types/block-string-assignment-to-DOMWindowTimers-setTimeout-setInterval.tentative.html
index f36ae94ea10..c24715718d1 100644
--- a/tests/wpt/web-platform-tests/trusted-types/block-string-assignment-to-DOMWindowTimers-setTimeout-setInterval.tentative.html
+++ b/tests/wpt/web-platform-tests/trusted-types/block-string-assignment-to-DOMWindowTimers-setTimeout-setInterval.tentative.html
@@ -54,13 +54,12 @@
     });
   }, "`window.setInterval(null)` throws.");
 
+  let policy = window.trustedTypes.createPolicy("default", { createScript: x => "0" });
   // After default policy creation string assignment implicitly calls createScript.
   test(t => {
-    let policy = window.trustedTypes.createPolicy("default", { createScript: createScriptJS }, true);
     setTimeout(INPUTS.SCRIPT);
     setInterval(INPUTS.SCRIPT);
   }, "`setTimeout(string)`, `setInterval(string)` via default policy (successful Script transformation).");
-
   // After default policy creation null assignment implicitly calls createScript.
   test(t => {
     setTimeout(null);
diff --git a/tests/wpt/web-platform-tests/urlpattern/input.https.any.js b/tests/wpt/web-platform-tests/urlpattern/input.https.any.js
deleted file mode 100644
index 71a8fb237b8..00000000000
--- a/tests/wpt/web-platform-tests/urlpattern/input.https.any.js
+++ /dev/null
@@ -1,88 +0,0 @@
-// META: global=window,worker
-// META: script=resources/utils.js
-
-// This file attempts to test the different ways you can pass input values
-// to be matched; e.g. as strings vs structured component parts.
-
-test(() => {
-  runTest({ pathname: '/foo/bar' }, [
-    { input: "https://example.com/foo/bar", expected: true },
-    { input: "https://example.com/foo/bar/baz", expected: false },
-  ]);
-}, "init single component, input string");
-
-test(() => {
-  runTest({ pathname: '/foo/bar' }, [
-    { input: { pathname: '/foo/bar' }, expected: true },
-    { input: { pathname: '/foo/bar/baz' }, expected: false },
-  ]);
-}, "init single component, input single component");
-
-test(() => {
-  runTest({ pathname: '/foo/bar' }, [
-    { input: { hostname: 'example.com', pathname: '/foo/bar' },
-      expected: true },
-    { input: { hostname: 'example.com', pathname: '/foo/bar/baz' },
-      expected: false },
-  ]);
-}, "init single component, input two components");
-
-test(() => {
-  runTest({ pathname: '/foo/bar' }, [
-    { input: { pathname: '/foo/bar', baseURL: 'https://example.com' },
-      expected: true },
-    { input: { pathname: '/foo/bar/baz', baseURL: 'https://example.com' },
-      expected: false },
-  ]);
-}, "init single component, input baseURL and single component");
-
-test(() => {
-  runTest({ pathname: '/foo/bar', baseURL: 'https://example.com?query#hash' }, [
-    { input: "https://example.com/foo/bar", expected: true },
-    { input: "https://example.com/foo/bar/baz", expected: false },
-    { input: "https://example2.com/foo/bar", expected: false },
-    { input: "http://example.com/foo/bar", expected: false },
-  ]);
-}, "init baseURL and single component, input string");
-
-test(() => {
-  runTest({ pathname: '/foo/bar', baseURL: 'https://example.com?query#hash' }, [
-    { input: { pathname: '/foo/bar' }, expected: false },
-    { input: { pathname: '/foo/bar/baz' }, expected: false },
-  ]);
-}, "init baseURL and single component, input single component");
-
-test(() => {
-  runTest({ pathname: '/foo/bar', baseURL: 'https://example.com?query#hash' }, [
-    { input: { hostname: 'example.com', pathname: '/foo/bar' },
-      expected: false },
-    { input: { hostname: 'example.com', pathname: '/foo/bar/baz' },
-      expected: false },
-    { input: { hostname: 'example2.com', pathname: '/foo/bar' },
-      expected: false },
-  ]);
-}, "init baseURL and single component, input two components");
-
-test(() => {
-  runTest({ pathname: '/foo/bar', baseURL: 'https://example.com?query#hash' }, [
-    { input: { protocol: 'https', hostname: 'example.com',
-               pathname: '/foo/bar' },
-      expected: true },
-    { input: { protocol: 'https', hostname: 'example.com',
-               pathname: '/foo/bar/baz' },
-      expected: false },
-  ]);
-}, "init single component, input three components");
-
-test(() => {
-  runTest({ pathname: '/foo/bar', baseURL: 'https://example.com?query#hash' }, [
-    { input: { pathname: '/foo/bar', baseURL: 'https://example.com' },
-      expected: true },
-    { input: { pathname: '/foo/bar/baz', baseURL: 'https://example.com' },
-      expected: false },
-    { input: { pathname: '/foo/bar', baseURL: 'https://example2.com' },
-      expected: false },
-    { input: { pathname: '/foo/bar', baseURL: 'http://example.com' },
-      expected: false },
-  ]);
-}, "init baseURL and single component, input baseURL and single component");
diff --git a/tests/wpt/web-platform-tests/urlpattern/pathname.https.any.js b/tests/wpt/web-platform-tests/urlpattern/pathname.https.any.js
deleted file mode 100644
index 5de41ccc438..00000000000
--- a/tests/wpt/web-platform-tests/urlpattern/pathname.https.any.js
+++ /dev/null
@@ -1,139 +0,0 @@
-// META: global=window,worker
-// META: script=resources/utils.js
-
-test(() => {
-  runTest({ pathname: '/foo/bar' }, [
-    { input: { pathname: '/foo/bar' }, expected: true },
-    { input: { pathname: '/foo/ba' }, expected: false },
-    { input: { pathname: '/foo/bar/' }, expected: false },
-    { input: { pathname: '/foo/bar/baz' }, expected: false },
-  ]);
-}, "fixed string");
-
-test(() => {
-  runTest({ pathname: '/foo/:bar' }, [
-    { input: { pathname: '/foo/bar' }, expected: true },
-    { input: { pathname: '/foo/index.html' }, expected: true },
-    { input: { pathname: '/foo/bar/' }, expected: false },
-    { input: { pathname: '/foo/' }, expected: false },
-  ]);
-}, "named group");
-
-test(() => {
-  runTest({ pathname: '/foo/(.*)' }, [
-    { input: { pathname: '/foo/bar' }, expected: true },
-    { input: { pathname: '/foo/bar/baz' }, expected: true },
-    { input: { pathname: '/foo/' }, expected: true },
-    { input: { pathname: '/foo' }, expected: false },
-  ]);
-}, "regexp group");
-
-test(() => {
-  runTest({ pathname: '/foo/:bar(.*)' }, [
-    { input: { pathname: '/foo/bar' }, expected: true },
-    { input: { pathname: '/foo/bar/baz' }, expected: true },
-    { input: { pathname: '/foo/' }, expected: true },
-    { input: { pathname: '/foo' }, expected: false },
-  ]);
-}, "named regexp group");
-
-test(() => {
-  runTest({ pathname: '/foo/:bar?' }, [
-    { input: { pathname: '/foo/bar' }, expected: true },
-    { input: { pathname: '/foo' }, expected: true },
-    { input: { pathname: '/foo/' }, expected: false },
-    { input: { pathname: '/foobar' }, expected: false },
-    { input: { pathname: '/foo/bar/baz' }, expected: false },
-  ]);
-}, "optional named group");
-
-test(() => {
-  runTest({ pathname: '/foo/:bar+' }, [
-    { input: { pathname: '/foo/bar' }, expected: true },
-    { input: { pathname: '/foo/bar/baz' }, expected: true },
-    { input: { pathname: '/foo' }, expected: false },
-    { input: { pathname: '/foo/' }, expected: false },
-    { input: { pathname: '/foobar' }, expected: false },
-  ]);
-}, "repeated named group");
-
-test(() => {
-  runTest({ pathname: '/foo/:bar*' }, [
-    { input: { pathname: '/foo/bar' }, expected: true },
-    { input: { pathname: '/foo/bar/baz' }, expected: true },
-    { input: { pathname: '/foo' }, expected: true },
-    { input: { pathname: '/foo/' }, expected: false },
-    { input: { pathname: '/foobar' }, expected: false },
-  ]);
-}, "optional repeated named group");
-
-test(() => {
-  runTest({ pathname: '/foo/(.*)?' }, [
-    { input: { pathname: '/foo/bar' }, expected: true },
-    { input: { pathname: '/foo/bar/baz' }, expected: true },
-    { input: { pathname: '/foo/' }, expected: true },
-    { input: { pathname: '/foo' }, expected: true },
-    { input: { pathname: '/fo' }, expected: false },
-    { input: { pathname: '/foobar' }, expected: false },
-  ]);
-}, "optional regexp group");
-
-test(() => {
-  runTest({ pathname: '/foo/(.*)+' }, [
-    { input: { pathname: '/foo/bar' }, expected: true },
-    { input: { pathname: '/foo/bar/baz' }, expected: true },
-    { input: { pathname: '/foo/' }, expected: true },
-    { input: { pathname: '/foo' }, expected: false },
-    { input: { pathname: '/fo' }, expected: false },
-    { input: { pathname: '/foobar' }, expected: false },
-  ]);
-}, "repeated regexp group");
-
-test(() => {
-  runTest({ pathname: '/foo/(.*)*' }, [
-    { input: { pathname: '/foo/bar' }, expected: true },
-    { input: { pathname: '/foo/bar/baz' }, expected: true },
-    { input: { pathname: '/foo/' }, expected: true },
-    { input: { pathname: '/foo' }, expected: true },
-    { input: { pathname: '/fo' }, expected: false },
-    { input: { pathname: '/foobar' }, expected: false },
-  ]);
-}, "optional repeated regexp group");
-
-test(() => {
-  runTest({ pathname: '/foo{/bar}' }, [
-    { input: { pathname: '/foo/bar' }, expected: true },
-    { input: { pathname: '/foo/bar/baz' }, expected: false },
-    { input: { pathname: '/foo/' }, expected: false },
-    { input: { pathname: '/foo' }, expected: false },
-  ]);
-}, "group");
-
-test(() => {
-  runTest({ pathname: '/foo{/bar}?' }, [
-    { input: { pathname: '/foo/bar' }, expected: true },
-    { input: { pathname: '/foo/bar/baz' }, expected: false },
-    { input: { pathname: '/foo' }, expected: true },
-    { input: { pathname: '/foo/' }, expected: false },
-  ]);
-}, "optional group");
-
-test(() => {
-  runTest({ pathname: '/foo{/bar}+' }, [
-    { input: { pathname: '/foo/bar' }, expected: true },
-    { input: { pathname: '/foo/bar/bar' }, expected: true },
-    { input: { pathname: '/foo/bar/baz' }, expected: false },
-    { input: { pathname: '/foo' }, expected: false },
-    { input: { pathname: '/foo/' }, expected: false },
-  ]);
-}, "repeated group");
-
-test(() => {
-  runTest({ pathname: '/foo{/bar}*' }, [
-    { input: { pathname: '/foo/bar' }, expected: true },
-    { input: { pathname: '/foo/bar/bar' }, expected: true },
-    { input: { pathname: '/foo/bar/baz' }, expected: false },
-    { input: { pathname: '/foo' }, expected: true },
-    { input: { pathname: '/foo/' }, expected: false },
-  ]);
-}, "repeated optional group");
diff --git a/tests/wpt/web-platform-tests/urlpattern/resources/urlpatterntestdata.json b/tests/wpt/web-platform-tests/urlpattern/resources/urlpatterntestdata.json
new file mode 100644
index 00000000000..66038e03d23
--- /dev/null
+++ b/tests/wpt/web-platform-tests/urlpattern/resources/urlpatterntestdata.json
@@ -0,0 +1,611 @@
+[
+  {
+    "pattern": { "pathname": "/foo/bar" },
+    "input": { "pathname": "/foo/bar" },
+    "expected": {
+      "input": { "pathname": "/foo/bar" },
+      "pathname": { "input": "/foo/bar", "groups": {} }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo/bar" },
+    "input": { "pathname": "/foo/ba" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo/bar" },
+    "input": { "pathname": "/foo/bar/" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo/bar" },
+    "input": { "pathname": "/foo/bar/baz" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo/bar" },
+    "input": "https://example.com/foo/bar",
+    "expected": {
+      "input": "https://example.com/foo/bar",
+      "hostname": { "input": "example.com", "groups": { "0": "example.com" } },
+      "pathname": { "input": "/foo/bar", "groups": {} },
+      "protocol": { "input": "https", "groups": { "0": "https" } }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo/bar" },
+    "input": "https://example.com/foo/bar/baz",
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo/bar" },
+    "input": { "hostname": "example.com", "pathname": "/foo/bar" },
+    "expected": {
+      "input": { "hostname": "example.com", "pathname": "/foo/bar" },
+      "hostname": { "input": "example.com", "groups": { "0": "example.com" } },
+      "pathname": { "input": "/foo/bar", "groups": {} }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo/bar" },
+    "input": { "hostname": "example.com", "pathname": "/foo/bar/baz" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo/bar" },
+    "input": { "pathname": "/foo/bar", "baseURL": "https://example.com" },
+    "expected": {
+      "input": { "pathname": "/foo/bar", "baseURL": "https://example.com" },
+      "hostname": { "input": "example.com", "groups": { "0": "example.com" } },
+      "pathname": { "input": "/foo/bar", "groups": {} },
+      "protocol": { "input": "https", "groups": { "0": "https" } }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo/bar" },
+    "input": { "pathname": "/foo/bar/baz", "baseURL": "https://example.com" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo/bar",
+                 "baseURL": "https://example.com?query#hash" },
+    "input": { "pathname": "/foo/bar" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo/bar",
+                 "baseURL": "https://example.com?query#hash" },
+    "input": { "hostname": "example.com", "pathname": "/foo/bar" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo/bar",
+                 "baseURL": "https://example.com?query#hash" },
+    "input": { "protocol": "https", "hostname": "example.com",
+               "pathname": "/foo/bar" },
+    "expected": {
+      "input": { "protocol": "https", "hostname": "example.com",
+                 "pathname": "/foo/bar" },
+      "exactly_empty_components": [ "username", "password", "port" ],
+      "hostname": { "input": "example.com", "groups": {} },
+      "pathname": { "input": "/foo/bar", "groups": {} },
+      "protocol": { "input": "https", "groups": {} }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo/bar",
+                 "baseURL": "https://example.com?query#hash" },
+    "input": { "protocol": "https", "hostname": "example.com",
+               "pathname": "/foo/bar/baz" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo/bar",
+                 "baseURL": "https://example.com?query#hash" },
+    "input": { "protocol": "https", "hostname": "example.com",
+               "pathname": "/foo/bar", "search": "otherquery",
+               "hash": "otherhash" },
+    "expected": {
+      "input": { "protocol": "https", "hostname": "example.com",
+                 "pathname": "/foo/bar", "search": "otherquery",
+                 "hash": "otherhash" },
+      "exactly_empty_components": [ "username", "password", "port" ],
+      "hash": { "input": "otherhash", "groups": { "0": "otherhash" } },
+      "hostname": { "input": "example.com", "groups": {} },
+      "pathname": { "input": "/foo/bar", "groups": {} },
+      "protocol": { "input": "https", "groups": {} },
+      "search": { "input": "otherquery", "groups": { "0": "otherquery" } }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo/bar",
+                 "baseURL": "https://example.com?query#hash" },
+    "input": "https://example.com/foo/bar",
+    "expected": {
+      "input": "https://example.com/foo/bar",
+      "exactly_empty_components": [ "username", "password", "port" ],
+      "hostname": { "input": "example.com", "groups": {} },
+      "pathname": { "input": "/foo/bar", "groups": {} },
+      "protocol": { "input": "https", "groups": {} }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo/bar",
+                 "baseURL": "https://example.com?query#hash" },
+    "input": "https://example.com/foo/bar?otherquery#otherhash",
+    "expected": {
+      "input": "https://example.com/foo/bar?otherquery#otherhash",
+      "exactly_empty_components": [ "username", "password", "port" ],
+      "hash": { "input": "otherhash", "groups": { "0": "otherhash" } },
+      "hostname": { "input": "example.com", "groups": {} },
+      "pathname": { "input": "/foo/bar", "groups": {} },
+      "protocol": { "input": "https", "groups": {} },
+      "search": { "input": "otherquery", "groups": { "0": "otherquery" } }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo/bar",
+                 "baseURL": "https://example.com?query#hash" },
+    "input": "https://example.com/foo/bar/baz",
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo/bar",
+                 "baseURL": "https://example.com?query#hash" },
+    "input": "https://other.com/foo/bar",
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo/bar",
+                 "baseURL": "https://example.com?query#hash" },
+    "input": "http://other.com/foo/bar",
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo/bar",
+                 "baseURL": "https://example.com?query#hash" },
+    "input": { "pathname": "/foo/bar", "baseURL": "https://example.com" },
+    "expected": {
+      "input": { "pathname": "/foo/bar", "baseURL": "https://example.com" },
+      "exactly_empty_components": [ "username", "password", "port" ],
+      "hostname": { "input": "example.com", "groups": {} },
+      "pathname": { "input": "/foo/bar", "groups": {} },
+      "protocol": { "input": "https", "groups": {} }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo/bar",
+                 "baseURL": "https://example.com?query#hash" },
+    "input": { "pathname": "/foo/bar/baz", "baseURL": "https://example.com" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo/bar",
+                 "baseURL": "https://example.com?query#hash" },
+    "input": { "pathname": "/foo/bar", "baseURL": "https://other.com" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo/bar",
+                 "baseURL": "https://example.com?query#hash" },
+    "input": { "pathname": "/foo/bar", "baseURL": "http://example.com" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo/:bar" },
+    "input": { "pathname": "/foo/bar" },
+    "expected": {
+      "input": { "pathname": "/foo/bar" },
+      "pathname": { "input": "/foo/bar", "groups": { "bar": "bar" } }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo/:bar" },
+    "input": { "pathname": "/foo/index.html" },
+    "expected": {
+      "input": { "pathname": "/foo/index.html" },
+      "pathname": { "input": "/foo/index.html", "groups": { "bar": "index.html" } }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo/:bar" },
+    "input": { "pathname": "/foo/bar/" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo/:bar" },
+    "input": { "pathname": "/foo/" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo/(.*)" },
+    "input": { "pathname": "/foo/bar" },
+    "expected": {
+      "input": { "pathname": "/foo/bar" },
+      "pathname": { "input": "/foo/bar", "groups": { "0": "bar" } }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo/(.*)" },
+    "input": { "pathname": "/foo/bar/baz" },
+    "expected": {
+      "input": { "pathname": "/foo/bar/baz" },
+      "pathname": { "input": "/foo/bar/baz", "groups": { "0": "bar/baz" } }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo/(.*)" },
+    "input": { "pathname": "/foo/" },
+    "expected": {
+      "input": { "pathname": "/foo/" },
+      "pathname": { "input": "/foo/", "groups": { "0": "" } }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo/(.*)" },
+    "input": { "pathname": "/foo" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo/:bar(.*)" },
+    "input": { "pathname": "/foo/bar" },
+    "expected": {
+      "input": { "pathname": "/foo/bar" },
+      "pathname": { "input": "/foo/bar", "groups": { "bar": "bar" } }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo/:bar(.*)" },
+    "input": { "pathname": "/foo/bar/baz" },
+    "expected": {
+      "input": { "pathname": "/foo/bar/baz" },
+      "pathname": { "input": "/foo/bar/baz", "groups": { "bar": "bar/baz" } }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo/:bar(.*)" },
+    "input": { "pathname": "/foo/" },
+    "expected": {
+      "input": { "pathname": "/foo/" },
+      "pathname": { "input": "/foo/", "groups": { "bar": "" } }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo/:bar(.*)" },
+    "input": { "pathname": "/foo" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo/:bar?" },
+    "input": { "pathname": "/foo/bar" },
+    "expected": {
+      "input": { "pathname": "/foo/bar" },
+      "pathname": { "input": "/foo/bar", "groups": { "bar": "bar" } }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo/:bar?" },
+    "input": { "pathname": "/foo" },
+    "expected": {
+      "input": { "pathname": "/foo" },
+      "pathname": { "input": "/foo", "groups": { "bar": "" } }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo/:bar?" },
+    "input": { "pathname": "/foo/" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo/:bar?" },
+    "input": { "pathname": "/foobar" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo/:bar?" },
+    "input": { "pathname": "/foo/bar/baz" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo/:bar+" },
+    "input": { "pathname": "/foo/bar" },
+    "expected": {
+      "input": { "pathname": "/foo/bar" },
+      "pathname": { "input": "/foo/bar", "groups": { "bar": "bar" } }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo/:bar+" },
+    "input": { "pathname": "/foo/bar/baz" },
+    "expected": {
+      "input": { "pathname": "/foo/bar/baz" },
+      "pathname": { "input": "/foo/bar/baz", "groups": { "bar": "bar/baz" } }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo/:bar+" },
+    "input": { "pathname": "/foo" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo/:bar+" },
+    "input": { "pathname": "/foo/" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo/:bar+" },
+    "input": { "pathname": "/foobar" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo/:bar*" },
+    "input": { "pathname": "/foo/bar" },
+    "expected": {
+      "input": { "pathname": "/foo/bar" },
+      "pathname": { "input": "/foo/bar", "groups": { "bar": "bar" } }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo/:bar*" },
+    "input": { "pathname": "/foo/bar/baz" },
+    "expected": {
+      "input": { "pathname": "/foo/bar/baz" },
+      "pathname": { "input": "/foo/bar/baz", "groups": { "bar": "bar/baz" } }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo/:bar*" },
+    "input": { "pathname": "/foo" },
+    "expected": {
+      "input": { "pathname": "/foo" },
+      "pathname": { "input": "/foo", "groups": { "bar": "" } }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo/:bar*" },
+    "input": { "pathname": "/foo/" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo/:bar*" },
+    "input": { "pathname": "/foobar" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo/(.*)?" },
+    "input": { "pathname": "/foo/bar" },
+    "expected": {
+      "input": { "pathname": "/foo/bar" },
+      "pathname": { "input": "/foo/bar", "groups": { "0": "bar" } }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo/(.*)?" },
+    "input": { "pathname": "/foo/bar/baz" },
+    "expected": {
+      "input": { "pathname": "/foo/bar/baz" },
+      "pathname": { "input": "/foo/bar/baz", "groups": { "0": "bar/baz" } }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo/(.*)?" },
+    "input": { "pathname": "/foo" },
+    "expected": {
+      "input": { "pathname": "/foo" },
+      "pathname": { "input": "/foo", "groups": { "0": "" } }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo/(.*)?" },
+    "input": { "pathname": "/foo/" },
+    "expected": {
+      "input": { "pathname": "/foo/" },
+      "pathname": { "input": "/foo/", "groups": { "0": "" } }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo/(.*)?" },
+    "input": { "pathname": "/foobar" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo/(.*)?" },
+    "input": { "pathname": "/fo" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo/(.*)+" },
+    "input": { "pathname": "/foo/bar" },
+    "expected": {
+      "input": { "pathname": "/foo/bar" },
+      "pathname": { "input": "/foo/bar", "groups": { "0": "bar" } }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo/(.*)+" },
+    "input": { "pathname": "/foo/bar/baz" },
+    "expected": {
+      "input": { "pathname": "/foo/bar/baz" },
+      "pathname": { "input": "/foo/bar/baz", "groups": { "0": "bar/baz" } }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo/(.*)+" },
+    "input": { "pathname": "/foo" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo/(.*)+" },
+    "input": { "pathname": "/foo/" },
+    "expected": {
+      "input": { "pathname": "/foo/" },
+      "pathname": { "input": "/foo/", "groups": { "0": "" } }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo/(.*)+" },
+    "input": { "pathname": "/foobar" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo/(.*)+" },
+    "input": { "pathname": "/fo" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo/(.*)*" },
+    "input": { "pathname": "/foo/bar" },
+    "expected": {
+      "input": { "pathname": "/foo/bar" },
+      "pathname": { "input": "/foo/bar", "groups": { "0": "bar" } }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo/(.*)*" },
+    "input": { "pathname": "/foo/bar/baz" },
+    "expected": {
+      "input": { "pathname": "/foo/bar/baz" },
+      "pathname": { "input": "/foo/bar/baz", "groups": { "0": "bar/baz" } }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo/(.*)*" },
+    "input": { "pathname": "/foo" },
+    "expected": {
+      "input": { "pathname": "/foo" },
+      "pathname": { "input": "/foo", "groups": { "0": "" } }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo/(.*)*" },
+    "input": { "pathname": "/foo/" },
+    "expected": {
+      "input": { "pathname": "/foo/" },
+      "pathname": { "input": "/foo/", "groups": { "0": "" } }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo/(.*)*" },
+    "input": { "pathname": "/foobar" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo/(.*)*" },
+    "input": { "pathname": "/fo" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo{/bar}" },
+    "input": { "pathname": "/foo/bar" },
+    "expected": {
+      "input": { "pathname": "/foo/bar" },
+      "pathname": { "input": "/foo/bar", "groups": {} }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo{/bar}" },
+    "input": { "pathname": "/foo/bar/baz" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo{/bar}" },
+    "input": { "pathname": "/foo" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo{/bar}" },
+    "input": { "pathname": "/foo/" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo{/bar}?" },
+    "input": { "pathname": "/foo/bar" },
+    "expected": {
+      "input": { "pathname": "/foo/bar" },
+      "pathname": { "input": "/foo/bar", "groups": {} }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo{/bar}?" },
+    "input": { "pathname": "/foo/bar/baz" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo{/bar}?" },
+    "input": { "pathname": "/foo" },
+    "expected": {
+      "input": { "pathname": "/foo" },
+      "pathname": { "input": "/foo", "groups": {} }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo{/bar}?" },
+    "input": { "pathname": "/foo/" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo{/bar}+" },
+    "input": { "pathname": "/foo/bar" },
+    "expected": {
+      "input": { "pathname": "/foo/bar" },
+      "pathname": { "input": "/foo/bar", "groups": {} }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo{/bar}+" },
+    "input": { "pathname": "/foo/bar/bar" },
+    "expected": {
+      "input": { "pathname": "/foo/bar/bar" },
+      "pathname": { "input": "/foo/bar/bar", "groups": {} }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo{/bar}+" },
+    "input": { "pathname": "/foo/bar/baz" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo{/bar}+" },
+    "input": { "pathname": "/foo" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo{/bar}+" },
+    "input": { "pathname": "/foo/" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo{/bar}*" },
+    "input": { "pathname": "/foo/bar" },
+    "expected": {
+      "input": { "pathname": "/foo/bar" },
+      "pathname": { "input": "/foo/bar", "groups": {} }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo{/bar}*" },
+    "input": { "pathname": "/foo/bar/bar" },
+    "expected": {
+      "input": { "pathname": "/foo/bar/bar" },
+      "pathname": { "input": "/foo/bar/bar", "groups": {} }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo{/bar}*" },
+    "input": { "pathname": "/foo/bar/baz" },
+    "expected": null
+  },
+  {
+    "pattern": { "pathname": "/foo{/bar}*" },
+    "input": { "pathname": "/foo" },
+    "expected": {
+      "input": { "pathname": "/foo" },
+      "pathname": { "input": "/foo", "groups": {} }
+    }
+  },
+  {
+    "pattern": { "pathname": "/foo{/bar}*" },
+    "input": { "pathname": "/foo/" },
+    "expected": null
+  }
+]
diff --git a/tests/wpt/web-platform-tests/urlpattern/resources/utils.js b/tests/wpt/web-platform-tests/urlpattern/resources/utils.js
deleted file mode 100644
index 9132a52816e..00000000000
--- a/tests/wpt/web-platform-tests/urlpattern/resources/utils.js
+++ /dev/null
@@ -1,7 +0,0 @@
-function runTest(pattern, expected_list) {
-  const p = new URLPattern(pattern);
-  for (let entry of expected_list) {
-    assert_equals(p.test(entry.input), entry.expected,
-                  `input: ${JSON.stringify(entry.input)}`);
-  }
-}
diff --git a/tests/wpt/web-platform-tests/urlpattern/urlpattern.https.any.js b/tests/wpt/web-platform-tests/urlpattern/urlpattern.https.any.js
new file mode 100644
index 00000000000..27b03d0ff03
--- /dev/null
+++ b/tests/wpt/web-platform-tests/urlpattern/urlpattern.https.any.js
@@ -0,0 +1,81 @@
+// META: global=window,worker
+
+function runTests(data) {
+  for (let entry of data) {
+    test(function() {
+      const pattern = new URLPattern(entry.pattern);
+
+      // First, validate the test() method by converting the expected result to
+      // a truthy value.
+      assert_equals(pattern.test(entry.input), !!entry.expected,
+                    'test() result');
+
+      // Next, start validating the exec() method.
+      const result = pattern.exec(entry.input);
+
+      // On a failed match exec() returns null.
+      if (!entry.expected) {
+        assert_equals(result, entry.expected, 'exec() failed match result');
+        return;
+      }
+
+      // Next verify the result.input is correct.  This may be a structured
+      // URLPatternInit dictionary object or a URL string.
+      if (typeof entry.expected.input === 'object') {
+        assert_object_equals(result.input, entry.expected.input,
+                             'exec() result.input');
+      } else {
+        assert_equals(result.input, entry.expected.input,
+                      'exec() result.input');
+      }
+
+      // Next we will compare the URLPatternComponentResult for each of these
+      // expected components.
+      const component_list = [
+        'protocol',
+        'username',
+        'password',
+        'hostname',
+        'password',
+        'pathname',
+        'search',
+        'hash',
+      ];
+
+      for (let component of component_list) {
+        let expected_obj = entry.expected[component];
+
+        // If the test expectations don't include a component object, then
+        // we auto-generate one.  This is convenient for the many cases
+        // where the pattern has a default wildcard or empty string pattern
+        // for a component and the input is essentially empty.
+        if (!expected_obj) {
+          // We must treat pathname specially since it always has at least one
+          // slash.
+          if (component === 'pathname')
+            expected_obj = { input: '/', groups: {} };
+          else
+            expected_obj = { input: '', groups: {} };
+
+          // Next, we must treat default wildcards differently than empty string
+          // patterns.  The wildcard results in a capture group, but the empty
+          // string pattern does not.  The expectation object must list which
+          // components should be empty instead of wildcards in
+          // |exactly_empty_components|.
+          if (!entry.expected.exactly_empty_components ||
+              !entry.expected.exactly_empty_components.includes(component)) {
+            expected_obj.groups['0'] = '';
+          }
+        }
+        assert_object_equals(result[component], expected_obj,
+                             `exec() result for ${component}`);
+      }
+    }, `Pattern: ${JSON.stringify(entry.pattern)} Input: ${JSON.stringify(entry.input)}`);
+  }
+}
+
+promise_test(async function() {
+  const response = await fetch('resources/urlpatterntestdata.json');
+  const data = await response.json();
+  runTests(data);
+}, 'Loading data...');
diff --git a/tests/wpt/web-platform-tests/web-bundle/resources/generate-test-wbns.sh b/tests/wpt/web-platform-tests/web-bundle/resources/generate-test-wbns.sh
index 8fc28bb9db7..3c8a3ea68d6 100755
--- a/tests/wpt/web-platform-tests/web-bundle/resources/generate-test-wbns.sh
+++ b/tests/wpt/web-platform-tests/web-bundle/resources/generate-test-wbns.sh
@@ -64,3 +64,9 @@ gen-bundle \
   -primaryURL $wpt_test_http_origin/web-bundle/resources/wbn/resource.js \
   -dir nested/ \
   -o wbn/nested-main.wbn
+
+gen-bundle \
+  -version b1 \
+  -har urn-uuid.har \
+  -primaryURL urn:uuid:020111b3-437a-4c5c-ae07-adb6bbffb720 \
+  -o wbn/urn-uuid.wbn
diff --git a/tests/wpt/web-platform-tests/web-bundle/resources/urn-uuid.har b/tests/wpt/web-platform-tests/web-bundle/resources/urn-uuid.har
new file mode 100644
index 00000000000..e0cea3699ae
--- /dev/null
+++ b/tests/wpt/web-platform-tests/web-bundle/resources/urn-uuid.har
@@ -0,0 +1,25 @@
+{
+  "log": {
+    "entries": [
+      {
+        "request": {
+          "method": "GET",
+          "url": "urn:uuid:020111b3-437a-4c5c-ae07-adb6bbffb720",
+          "headers": []
+        },
+        "response": {
+          "status": 200,
+          "headers": [
+            {
+              "name": "Content-type",
+              "value": "application/javascript"
+            }
+          ],
+          "content": {
+            "text": "window.report_result('OK');"
+          }
+        }
+      }
+    ]
+  }
+}
diff --git a/tests/wpt/web-platform-tests/web-bundle/resources/wbn/urn-uuid.wbn b/tests/wpt/web-platform-tests/web-bundle/resources/wbn/urn-uuid.wbn
new file mode 100644
index 00000000000..a4bd3efc9cc
Binary files /dev/null and b/tests/wpt/web-platform-tests/web-bundle/resources/wbn/urn-uuid.wbn differ
diff --git a/tests/wpt/web-platform-tests/web-bundle/subresource-loading/subresource-loading-from-web-bundle.tentative.html b/tests/wpt/web-platform-tests/web-bundle/subresource-loading/subresource-loading-from-web-bundle.tentative.html
index c2de0eb0994..53a9c1b2cc7 100644
--- a/tests/wpt/web-platform-tests/web-bundle/subresource-loading/subresource-loading-from-web-bundle.tentative.html
+++ b/tests/wpt/web-platform-tests/web-bundle/subresource-loading/subresource-loading-from-web-bundle.tentative.html
@@ -100,6 +100,16 @@
       assert_equals(module.result, 'resource1 from network');
     }, 'Subresource URL must be same-origin with bundle URL');
 
+    promise_test(async () => {
+      const url = 'urn:uuid:020111b3-437a-4c5c-ae07-adb6bbffb720';
+      const link = document.createElement('link');
+      link.rel = 'webbundle';
+      link.href = '../resources/wbn/urn-uuid.wbn';
+      link.resources = url;
+      document.body.appendChild(link);
+      assert_equals(await loadScriptAndWaitReport(url), 'OK');
+    }, 'Subresource loading with urn:uuid: URL');
+
     promise_test(async () => {
       const wbn_url = 'http://web-platform.test:8001/web-bundle/resources/wbn/subresource.wbn?test-resources-update';
       const resource_url = 'http://web-platform.test:8001/web-bundle/resources/wbn/submodule.js';