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 76b44d9e9cf..3605e8f3fc9 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: FAIL
+    expected: TIMEOUT
 
   [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-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-text/white-space/trailing-other-space-separators-break-spaces-012.html.ini b/tests/wpt/metadata-layout-2020/css/css-text/white-space/trailing-other-space-separators-break-spaces-012.html.ini
new file mode 100644
index 00000000000..c4ec0fbcc2f
--- /dev/null
+++ b/tests/wpt/metadata-layout-2020/css/css-text/white-space/trailing-other-space-separators-break-spaces-012.html.ini
@@ -0,0 +1,2 @@
+[trailing-other-space-separators-break-spaces-012.html]
+  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
new file mode 100644
index 00000000000..e38782d8c85
--- /dev/null
+++ b/tests/wpt/metadata-layout-2020/css/cssom-view/elementFromPoint-001.html.ini
@@ -0,0 +1,4 @@
+[elementFromPoint-001.html]
+  [CSSOM View - 5 - extensions to the Document interface]
+    expected: FAIL
+
diff --git a/tests/wpt/metadata-layout-2020/css/cssom-view/elementFromPosition.html.ini b/tests/wpt/metadata-layout-2020/css/cssom-view/elementFromPosition.html.ini
index c131078eace..23c61ede1a1 100644
--- a/tests/wpt/metadata-layout-2020/css/cssom-view/elementFromPosition.html.ini
+++ b/tests/wpt/metadata-layout-2020/css/cssom-view/elementFromPosition.html.ini
@@ -17,3 +17,6 @@
   [test the top of layer]
     expected: FAIL
 
+  [test some point of the element: top left corner]
+    expected: FAIL
+
diff --git a/tests/wpt/metadata-layout-2020/fetch/content-type/response.window.js.ini b/tests/wpt/metadata-layout-2020/fetch/content-type/response.window.js.ini
index d84872d87d6..9df578bb958 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
@@ -321,15 +321,21 @@
   [<iframe>: separate response Content-Type: text/plain */*;charset=gbk]
     expected: FAIL
 
-  [<iframe>: combined response Content-Type: */* text/html]
-    expected: FAIL
-
   [<iframe>: separate response Content-Type: text/html */*]
     expected: FAIL
 
-  [<iframe>: combined response Content-Type: text/html;" \\" text/plain]
-    expected: FAIL
-
   [<iframe>: combined response Content-Type: text/html;x=" text/plain]
     expected: FAIL
 
+  [<iframe>: combined response Content-Type: text/html */*]
+    expected: FAIL
+
+  [<iframe>: separate response Content-Type: text/html */*;charset=gbk]
+    expected: FAIL
+
+  [<iframe>: separate response Content-Type: text/plain */*]
+    expected: FAIL
+
+  [<iframe>: separate response Content-Type: text/html;x=" text/plain]
+    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 333df26fe72..30e1b851fd4 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
@@ -11,9 +11,3 @@
   [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%20no%0D%0AX-Content-Type-Options%3A%20nosniff]
-    expected: FAIL
-
-  [Content-Type-Options%3A%20nosniff]
-    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
deleted file mode 100644
index dc2e45516de..00000000000
--- a/tests/wpt/metadata-layout-2020/html/browsers/history/the-history-interface/traverse_the_history_5.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[traverse_the_history_5.html]
-  [Multiple history traversals, last would be aborted]
-    expected: FAIL
-
diff --git a/tests/wpt/metadata-layout-2020/html/browsers/origin/cross-origin-objects/cross-origin-objects-on-new-window.html.ini b/tests/wpt/metadata-layout-2020/html/browsers/origin/cross-origin-objects/cross-origin-objects-on-new-window.html.ini
deleted file mode 100644
index 735a9a75a2a..00000000000
--- a/tests/wpt/metadata-layout-2020/html/browsers/origin/cross-origin-objects/cross-origin-objects-on-new-window.html.ini
+++ /dev/null
@@ -1,2 +0,0 @@
-[cross-origin-objects-on-new-window.html]
-  expected: TIMEOUT
diff --git a/tests/wpt/metadata-layout-2020/html/interaction/focus/the-autofocus-attribute/supported-elements.html.ini b/tests/wpt/metadata-layout-2020/html/interaction/focus/the-autofocus-attribute/supported-elements.html.ini
index f45aaafe1c5..3538891dae8 100644
--- a/tests/wpt/metadata-layout-2020/html/interaction/focus/the-autofocus-attribute/supported-elements.html.ini
+++ b/tests/wpt/metadata-layout-2020/html/interaction/focus/the-autofocus-attribute/supported-elements.html.ini
@@ -1,4 +1,5 @@
 [supported-elements.html]
+  expected: TIMEOUT
   [Contenteditable element should support autofocus]
     expected: FAIL
 
@@ -9,7 +10,7 @@
     expected: FAIL
 
   [Area element should support autofocus]
-    expected: FAIL
+    expected: TIMEOUT
 
   [Host element with delegatesFocus should support autofocus]
     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 42ebcc9d57e..88f4ddd0e9a 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: TIMEOUT
+  expected: CRASH
   [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 338d283eb0e..295031c1812 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
@@ -1,4 +1,5 @@
 [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: FAIL
+    expected: TIMEOUT
 
diff --git a/tests/wpt/metadata-layout-2020/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_nonescaping-1.html.ini b/tests/wpt/metadata-layout-2020/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_nonescaping-1.html.ini
index 3080be9afc0..d913fcbb129 100644
--- a/tests/wpt/metadata-layout-2020/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_nonescaping-1.html.ini
+++ b/tests/wpt/metadata-layout-2020/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_nonescaping-1.html.ini
@@ -1,5 +1,5 @@
 [iframe_sandbox_popups_nonescaping-1.html]
-  expected: CRASH
+  expected: TIMEOUT
   [Check that popups from a sandboxed iframe do not escape the sandbox]
     expected: NOTRUN
 
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 7a36937927c..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
@@ -1,4 +1,5 @@
 [iframe_sandbox_popups_nonescaping-3.html]
+  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/webappapis/dynamic-markup-insertion/document-write/module-delayed.html.ini b/tests/wpt/metadata-layout-2020/html/webappapis/dynamic-markup-insertion/document-write/module-delayed.html.ini
new file mode 100644
index 00000000000..59a54fe88e4
--- /dev/null
+++ b/tests/wpt/metadata-layout-2020/html/webappapis/dynamic-markup-insertion/document-write/module-delayed.html.ini
@@ -0,0 +1,4 @@
+[module-delayed.html]
+  [async document.write in a module]
+    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 5602ea31dbe..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
@@ -4,5 +4,5 @@
     expected: TIMEOUT
 
   [The entry settings object while executing the compiled callback via Web IDL's invoke must be that of the node document]
-    expected: TIMEOUT
+    expected: FAIL
 
diff --git a/tests/wpt/metadata-layout-2020/html/webappapis/scripting/processing-model-2/integration-with-the-javascript-job-queue/promise-job-entry.html.ini b/tests/wpt/metadata-layout-2020/html/webappapis/scripting/processing-model-2/integration-with-the-javascript-job-queue/promise-job-entry.html.ini
index a1effd5f801..5ddb9bfeff6 100644
--- a/tests/wpt/metadata-layout-2020/html/webappapis/scripting/processing-model-2/integration-with-the-javascript-job-queue/promise-job-entry.html.ini
+++ b/tests/wpt/metadata-layout-2020/html/webappapis/scripting/processing-model-2/integration-with-the-javascript-job-queue/promise-job-entry.html.ini
@@ -1,9 +1,10 @@
 [promise-job-entry.html]
+  expected: TIMEOUT
   [Fulfillment handler on fulfilled promise]
     expected: FAIL
 
   [Rejection handler on pending-then-rejected promise]
-    expected: FAIL
+    expected: TIMEOUT
 
   [Sanity check: this all works as expected with no promises involved]
     expected: FAIL
@@ -15,5 +16,5 @@
     expected: FAIL
 
   [Fulfillment handler on pending-then-fulfilled promise]
-    expected: FAIL
+    expected: TIMEOUT
 
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 b7e13cf7726..f1281b5ae81 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
@@ -1,4 +1,5 @@
 [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/017.html.ini b/tests/wpt/metadata-layout-2020/webmessaging/with-ports/017.html.ini
new file mode 100644
index 00000000000..064cf47545b
--- /dev/null
+++ b/tests/wpt/metadata-layout-2020/webmessaging/with-ports/017.html.ini
@@ -0,0 +1,5 @@
+[017.html]
+  expected: TIMEOUT
+  [origin of the script that invoked the method, about:blank]
+    expected: TIMEOUT
+
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 d4f62ed7113..faa00f45ecf 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: FAIL
+    expected: TIMEOUT
 
   [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 d8b8c9675e0..6b441e3bc41 100644
--- a/tests/wpt/metadata/MANIFEST.json
+++ b/tests/wpt/metadata/MANIFEST.json
@@ -353622,7 +353622,7 @@
       []
      ],
      "conftest.py": [
-      "a9f4203f279cbadb702456b1d71d6aa60ed5d0ef",
+      "1baf6622b0599c44fb85d267288031a05e4243dc",
       []
      ],
      "harness.html": [
@@ -354028,7 +354028,7 @@
       []
      ],
      "wptserver.py": [
-      "d47e325fbef64a425ba91f21a49a6d27e03a7e3b",
+      "a504a76a46e00db8f9bb4a19dc9dca58ec1c8314",
       []
      ]
     },
@@ -358523,7 +358523,7 @@
        []
       ],
       "github_checks_output.py": [
-       "b34e33dd9e817a80ac60a022fbfb6f0cb9c13766",
+       "fcc6f8ce5911a24ee761889b184da42a03485071",
        []
       ],
       "sink_task.py": [
@@ -487209,13 +487209,6 @@
       {}
      ]
     ],
-    "longtask-before-observer.window.js": [
-     "b7d4eb9d1de1ac1b91a2e6c9b5d124413b6dc0b9",
-     [
-      "longtask-timing/longtask-before-observer.window.html",
-      {}
-     ]
-    ],
     "longtask-in-childiframe-crossorigin.html": [
      "d0fdf742804d722a6682e8f2b455284dc83fa4b9",
      [
@@ -489579,7 +489572,7 @@
      ]
     ],
     "MediaRecorder-stop.html": [
-     "ad6fa8809f6ad3af26969bbcb6a761280e5d705c",
+     "7e19bc0c054472fdf8161bff41f99f2e601c0abb",
      [
       null,
       {}
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-text/white-space/trailing-other-space-separators-break-spaces-012.html.ini b/tests/wpt/metadata/css/css-text/white-space/trailing-other-space-separators-break-spaces-012.html.ini
new file mode 100644
index 00000000000..c4ec0fbcc2f
--- /dev/null
+++ b/tests/wpt/metadata/css/css-text/white-space/trailing-other-space-separators-break-spaces-012.html.ini
@@ -0,0 +1,2 @@
+[trailing-other-space-separators-break-spaces-012.html]
+  expected: FAIL
diff --git a/tests/wpt/metadata/css/cssom-view/elementFromPoint-001.html.ini b/tests/wpt/metadata/css/cssom-view/elementFromPoint-001.html.ini
new file mode 100644
index 00000000000..e38782d8c85
--- /dev/null
+++ b/tests/wpt/metadata/css/cssom-view/elementFromPoint-001.html.ini
@@ -0,0 +1,4 @@
+[elementFromPoint-001.html]
+  [CSSOM View - 5 - extensions to the Document interface]
+    expected: FAIL
+
diff --git a/tests/wpt/metadata/css/cssom-view/elementFromPosition.html.ini b/tests/wpt/metadata/css/cssom-view/elementFromPosition.html.ini
index 85e94926cb3..5733d536fd3 100644
--- a/tests/wpt/metadata/css/cssom-view/elementFromPosition.html.ini
+++ b/tests/wpt/metadata/css/cssom-view/elementFromPosition.html.ini
@@ -21,3 +21,6 @@
   [test the top of layer]
     expected: FAIL
 
+  [test some point of the element: top left corner]
+    expected: FAIL
+
diff --git a/tests/wpt/metadata/fetch/content-type/response.window.js.ini b/tests/wpt/metadata/fetch/content-type/response.window.js.ini
index 342daf7a53c..1ca9519dafd 100644
--- a/tests/wpt/metadata/fetch/content-type/response.window.js.ini
+++ b/tests/wpt/metadata/fetch/content-type/response.window.js.ini
@@ -321,15 +321,21 @@
   [<iframe>: separate response Content-Type: text/plain */*;charset=gbk]
     expected: FAIL
 
-  [<iframe>: combined response Content-Type: */* text/html]
-    expected: FAIL
-
   [<iframe>: separate response Content-Type: text/html */*]
     expected: FAIL
 
-  [<iframe>: combined response Content-Type: text/html;" \\" text/plain]
-    expected: FAIL
-
   [<iframe>: combined response Content-Type: text/html;x=" text/plain]
     expected: FAIL
 
+  [<iframe>: combined response Content-Type: text/html */*]
+    expected: FAIL
+
+  [<iframe>: separate response Content-Type: text/html */*;charset=gbk]
+    expected: FAIL
+
+  [<iframe>: separate response Content-Type: text/plain */*]
+    expected: FAIL
+
+  [<iframe>: separate response Content-Type: text/html;x=" text/plain]
+    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 333df26fe72..30e1b851fd4 100644
--- a/tests/wpt/metadata/fetch/nosniff/parsing-nosniff.window.js.ini
+++ b/tests/wpt/metadata/fetch/nosniff/parsing-nosniff.window.js.ini
@@ -11,9 +11,3 @@
   [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%20no%0D%0AX-Content-Type-Options%3A%20nosniff]
-    expected: FAIL
-
-  [Content-Type-Options%3A%20nosniff]
-    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
deleted file mode 100644
index dc2e45516de..00000000000
--- a/tests/wpt/metadata/html/browsers/history/the-history-interface/traverse_the_history_5.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[traverse_the_history_5.html]
-  [Multiple history traversals, last would be aborted]
-    expected: FAIL
-
diff --git a/tests/wpt/metadata/html/browsers/origin/cross-origin-objects/cross-origin-objects-on-new-window.html.ini b/tests/wpt/metadata/html/browsers/origin/cross-origin-objects/cross-origin-objects-on-new-window.html.ini
deleted file mode 100644
index 735a9a75a2a..00000000000
--- a/tests/wpt/metadata/html/browsers/origin/cross-origin-objects/cross-origin-objects-on-new-window.html.ini
+++ /dev/null
@@ -1,2 +0,0 @@
-[cross-origin-objects-on-new-window.html]
-  expected: TIMEOUT
diff --git a/tests/wpt/metadata/html/interaction/focus/the-autofocus-attribute/supported-elements.html.ini b/tests/wpt/metadata/html/interaction/focus/the-autofocus-attribute/supported-elements.html.ini
index 6b68e9094e4..d1ca01ebc5f 100644
--- a/tests/wpt/metadata/html/interaction/focus/the-autofocus-attribute/supported-elements.html.ini
+++ b/tests/wpt/metadata/html/interaction/focus/the-autofocus-attribute/supported-elements.html.ini
@@ -1,4 +1,5 @@
 [supported-elements.html]
+  expected: TIMEOUT
   [Contenteditable element should support autofocus]
     expected: FAIL
 
@@ -9,7 +10,7 @@
     expected: FAIL
 
   [Area element should support autofocus]
-    expected: FAIL
+    expected: TIMEOUT
 
   [Host element with delegatesFocus should support autofocus]
     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 fc37df7e3fa..2a166bb97b7 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: TIMEOUT
+  expected: CRASH
   [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 f6a7aca3306..5f60c78e73c 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
@@ -1,5 +1,6 @@
 [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: FAIL
+    expected: TIMEOUT
 
diff --git a/tests/wpt/metadata/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_nonescaping-1.html.ini b/tests/wpt/metadata/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_nonescaping-1.html.ini
index 963d4cd20ef..9df1ac56f2a 100644
--- a/tests/wpt/metadata/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_nonescaping-1.html.ini
+++ b/tests/wpt/metadata/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_nonescaping-1.html.ini
@@ -1,6 +1,6 @@
 [iframe_sandbox_popups_nonescaping-1.html]
   type: testharness
-  expected: CRASH
+  expected: TIMEOUT
   [Check that popups from a sandboxed iframe do not escape the sandbox]
     expected: NOTRUN
 
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 dc856a3d5a3..e440b1e38c6 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 +1,6 @@
 [iframe_sandbox_popups_nonescaping-3.html]
   type: testharness
+  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/webappapis/dynamic-markup-insertion/document-write/module-delayed.html.ini b/tests/wpt/metadata/html/webappapis/dynamic-markup-insertion/document-write/module-delayed.html.ini
new file mode 100644
index 00000000000..59a54fe88e4
--- /dev/null
+++ b/tests/wpt/metadata/html/webappapis/dynamic-markup-insertion/document-write/module-delayed.html.ini
@@ -0,0 +1,4 @@
+[module-delayed.html]
+  [async document.write in a module]
+    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 edae5e5adcd..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
@@ -5,5 +5,5 @@
     expected: TIMEOUT
 
   [The entry settings object while executing the compiled callback via Web IDL's invoke must be that of the node document]
-    expected: TIMEOUT
+    expected: FAIL
 
diff --git a/tests/wpt/metadata/html/webappapis/scripting/processing-model-2/integration-with-the-javascript-job-queue/promise-job-entry.html.ini b/tests/wpt/metadata/html/webappapis/scripting/processing-model-2/integration-with-the-javascript-job-queue/promise-job-entry.html.ini
index a1effd5f801..5ddb9bfeff6 100644
--- a/tests/wpt/metadata/html/webappapis/scripting/processing-model-2/integration-with-the-javascript-job-queue/promise-job-entry.html.ini
+++ b/tests/wpt/metadata/html/webappapis/scripting/processing-model-2/integration-with-the-javascript-job-queue/promise-job-entry.html.ini
@@ -1,9 +1,10 @@
 [promise-job-entry.html]
+  expected: TIMEOUT
   [Fulfillment handler on fulfilled promise]
     expected: FAIL
 
   [Rejection handler on pending-then-rejected promise]
-    expected: FAIL
+    expected: TIMEOUT
 
   [Sanity check: this all works as expected with no promises involved]
     expected: FAIL
@@ -15,5 +16,5 @@
     expected: FAIL
 
   [Fulfillment handler on pending-then-fulfilled promise]
-    expected: FAIL
+    expected: TIMEOUT
 
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 b7e13cf7726..f1281b5ae81 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
@@ -1,4 +1,5 @@
 [audiocontext-not-fully-active.html]
+  expected: TIMEOUT
   [frame in navigated remote-site frame]
     expected: FAIL
 
diff --git a/tests/wpt/metadata/webmessaging/with-ports/017.html.ini b/tests/wpt/metadata/webmessaging/with-ports/017.html.ini
new file mode 100644
index 00000000000..064cf47545b
--- /dev/null
+++ b/tests/wpt/metadata/webmessaging/with-ports/017.html.ini
@@ -0,0 +1,5 @@
+[017.html]
+  expected: TIMEOUT
+  [origin of the script that invoked the method, about:blank]
+    expected: TIMEOUT
+
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/longtask-timing/longtask-before-observer.window.js b/tests/wpt/web-platform-tests/longtask-timing/longtask-before-observer.window.js
deleted file mode 100644
index b7d4eb9d1de..00000000000
--- a/tests/wpt/web-platform-tests/longtask-timing/longtask-before-observer.window.js
+++ /dev/null
@@ -1,16 +0,0 @@
-async_test(t => {
-  assert_implements(window.PerformanceLongTaskTiming, 'Longtasks are not supported.');
-  // Create a long task before any observer.
-  const begin = window.performance.now();
-  while (window.performance.now() < begin + 60);
-  // After a timeout, add an observer with buffered flag.
-  t.step_timeout(() => {
-    new PerformanceObserver(t.step_func_done(list => {
-      list.getEntries().forEach(entry => {
-        assert_equals(entry.entryType, 'longtask');
-        assert_equals(entry.name, 'self');
-        assert_greater_than(entry.duration, 50);
-      });
-    })).observe({type: 'longtask', buffered: true});
-  }, 0);
-}, 'PerformanceObserver with buffered flag can see previous longtask entries.');
diff --git a/tests/wpt/web-platform-tests/mediacapture-record/MediaRecorder-stop.html b/tests/wpt/web-platform-tests/mediacapture-record/MediaRecorder-stop.html
index ad6fa8809f6..7e19bc0c054 100644
--- a/tests/wpt/web-platform-tests/mediacapture-record/MediaRecorder-stop.html
+++ b/tests/wpt/web-platform-tests/mediacapture-record/MediaRecorder-stop.html
@@ -83,24 +83,24 @@
 
     promise_test(async t => {
         const recorder = new MediaRecorder(createVideoStream());
-        assert_throws_dom("InvalidStateError", () => { recorder.stop(); });
+        recorder.stop();
         await Promise.race([
             new Promise((_, reject) => recorder.onstop =
                 _ => reject(new Error("onstop should never have been called"))),
             new Promise(r => t.step_timeout(r, 0))]);
-    }, "MediaRecorder will fire an exception when stopped after creation");
+    }, "MediaRecorder will not fire an exception when stopped after creation");
 
     promise_test(async t => {
         const recorder = new MediaRecorder(createVideoStream());
         recorder.start();
         recorder.stop();
         let event = await new Promise(r => recorder.onstop = r);
-        assert_throws_dom("InvalidStateError", () => { recorder.stop(); });
+        recorder.stop();
         await Promise.race([
             new Promise((_, reject) => recorder.onstop =
                 _ => reject(new Error("onstop should never have been called"))),
             new Promise(r => t.step_timeout(r, 0))]);
-    }, "MediaRecorder will fire an exception when stopped after having just been stopped");
+    }, "MediaRecorder will not fire an exception when stopped after having just been stopped");
 
     promise_test(async t => {
         const stream = createVideoStream();
@@ -108,12 +108,12 @@
         recorder.start();
         stream.getVideoTracks()[0].stop();
         let event = await new Promise(r => recorder.onstop = r);
-        assert_throws_dom("InvalidStateError", () => { recorder.stop(); });
+        recorder.stop();
         await Promise.race([
             new Promise((_, reject) => recorder.onstop =
                 _ => reject(new Error("onstop should never have been called"))),
             new Promise(r => t.step_timeout(r, 0))]);
-    }, "MediaRecorder will fire an exception when stopped after having just been spontaneously stopped");
+    }, "MediaRecorder will not fire an exception when stopped after having just been spontaneously stopped");
 
     promise_test(async t => {
         const stream = await navigator.mediaDevices.getUserMedia({ audio: true, video: true });
diff --git a/tests/wpt/web-platform-tests/resources/test/conftest.py b/tests/wpt/web-platform-tests/resources/test/conftest.py
index a9f4203f279..1baf6622b05 100644
--- a/tests/wpt/web-platform-tests/resources/test/conftest.py
+++ b/tests/wpt/web-platform-tests/resources/test/conftest.py
@@ -25,6 +25,7 @@ import webdriver
 
 def pytest_addoption(parser):
     parser.addoption("--binary", action="store", default=None, help="path to browser binary")
+    parser.addoption("--headless", action="store_true", default=False, help="run browser in headless mode")
 
 
 def pytest_collect_file(path, parent):
@@ -45,9 +46,11 @@ def pytest_configure(config):
     config.proc = subprocess.Popen(["geckodriver"])
     config.add_cleanup(config.proc.kill)
 
-    capabilities = {"alwaysMatch": {"acceptInsecureCerts": True}}
+    capabilities = {"alwaysMatch": {"acceptInsecureCerts": True, "moz:firefoxOptions": {}}}
     if config.getoption("--binary"):
-        capabilities["alwaysMatch"]["moz:firefoxOptions"] = {"binary": config.getoption("--binary")}
+        capabilities["alwaysMatch"]["moz:firefoxOptions"]["binary"] = config.getoption("--binary")
+    if config.getoption("--headless"):
+        capabilities["alwaysMatch"]["moz:firefoxOptions"]["args"] = ["--headless"]
 
     config.driver = webdriver.Session("localhost", 4444,
                                       capabilities=capabilities)
diff --git a/tests/wpt/web-platform-tests/resources/test/wptserver.py b/tests/wpt/web-platform-tests/resources/test/wptserver.py
index d47e325fbef..a504a76a46e 100644
--- a/tests/wpt/web-platform-tests/resources/test/wptserver.py
+++ b/tests/wpt/web-platform-tests/resources/test/wptserver.py
@@ -24,6 +24,8 @@ class WPTServer(object):
     def start(self):
         self.devnull = open(os.devnull, 'w')
         wptserve_cmd = [os.path.join(self.wpt_root, 'wpt'), 'serve']
+        if sys.executable:
+            wptserve_cmd[0:0] = [sys.executable]
         logging.info('Executing %s' % ' '.join(wptserve_cmd))
         self.proc = subprocess.Popen(
             wptserve_cmd,
diff --git a/tests/wpt/web-platform-tests/tools/ci/tc/github_checks_output.py b/tests/wpt/web-platform-tests/tools/ci/tc/github_checks_output.py
index b34e33dd9e8..fcc6f8ce591 100644
--- a/tests/wpt/web-platform-tests/tools/ci/tc/github_checks_output.py
+++ b/tests/wpt/web-platform-tests/tools/ci/tc/github_checks_output.py
@@ -1,9 +1,11 @@
+import io
+from six import ensure_text
+
 MYPY = False
 if MYPY:
     # MYPY is set to True when run under Mypy.
-    from typing import Any
-    from typing import Optional
-    from typing import Text
+    from typing import AnyStr, Optional, Text
+
 
 class GitHubChecksOutputter(object):
     """Provides a method to output data to be shown in the GitHub Checks UI.
@@ -12,23 +14,27 @@ class GitHubChecksOutputter(object):
     to enable developers to quickly understand what has gone wrong. The output
     supports markdown format.
 
-    See https://docs.taskcluster.net/docs/reference/integrations/github/checks#custom-text-output-in-checks
+    https://docs.taskcluster.net/docs/reference/integrations/github/checks#custom-text-output-in-checks
     """
     def __init__(self, path):
         # type: (Text) -> None
         self.path = path
 
     def output(self, line):
-        # type: (Any) -> None
-        # TODO(stephenmcgruer): Once mypy 0.790 is released, we can change this
-        # to AnyStr, as that release teaches mypy about the mode flags of open.
-        # See https://github.com/python/typeshed/pull/4146
-        with open(self.path, 'a') as f:
-            f.write(line)
-            f.write('\n')
+        # type: (AnyStr) -> None
+        text = ensure_text(line)
+        # NOTE: mypy types the "text mode" of open() in Python 2 as BinaryIO,
+        # which makes sense as we cannot specify its encoding (it's
+        # platform-dependent), while io.open() is closer to open() in Python 3.
+        # TODO: use the built-in open() when we are Py3-only.
+        with io.open(self.path, mode="a") as f:
+            f.write(text)
+            f.write(u"\n")
 
 
 __outputter = None
+
+
 def get_gh_checks_outputter(filepath):
     # type: (Optional[Text]) -> Optional[GitHubChecksOutputter]
     """Return the outputter for GitHub Checks output, if enabled.