Update web-platform-tests to revision daac9dc806e9571ea856253fcc35a94e73d4f711

67 files changed, 1485 insertions, 146 deletions

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 a9e46713244..76b398963ae 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: FAIL
diff --git a/tests/wpt/metadata/FileAPI/url/url-with-fetch.any.js.ini b/tests/wpt/metadata/FileAPI/url/url-with-fetch.any.js.ini
index 947e223fb28..3a3d15b8406 100644
--- a/tests/wpt/metadata/FileAPI/url/url-with-fetch.any.js.ini
+++ b/tests/wpt/metadata/FileAPI/url/url-with-fetch.any.js.ini
@@ -14,6 +14,9 @@
   [Revoke blob URL after creating Request, will fetch]
     expected: FAIL
 
+  [Revoke blob URL after calling fetch, fetch should succeed]
+    expected: FAIL
+
 
 [url-with-fetch.any.html]
   [Untitled]
@@ -34,3 +37,6 @@
   [Revoke blob URL after creating Request, will fetch]
     expected: FAIL
 
+  [Revoke blob URL after calling fetch, fetch should succeed]
+    expected: FAIL
+
diff --git a/tests/wpt/metadata/MANIFEST.json b/tests/wpt/metadata/MANIFEST.json
index 30fa6ef6cc5..39d79ea92bf 100644
--- a/tests/wpt/metadata/MANIFEST.json
+++ b/tests/wpt/metadata/MANIFEST.json
@@ -48803,6 +48803,18 @@
      {}
     ]
    ],
+   "css/CSS2/floats/adjoining-floats-dynamic.html": [
+    [
+     "css/CSS2/floats/adjoining-floats-dynamic.html",
+     [
+      [
+       "/css/reference/ref-filled-green-100px-square.xht",
+       "=="
+      ]
+     ],
+     {}
+    ]
+   ],
    "css/CSS2/floats/float-no-content-beside-001.html": [
     [
      "css/CSS2/floats/float-no-content-beside-001.html",
@@ -95263,6 +95275,30 @@
      {}
     ]
    ],
+   "css/CSS2/text/bidi-span-001.html": [
+    [
+     "css/CSS2/text/bidi-span-001.html",
+     [
+      [
+       "/css/CSS2/text/bidi-span-001-ref.html",
+       "=="
+      ]
+     ],
+     {}
+    ]
+   ],
+   "css/CSS2/text/bidi-span-002.html": [
+    [
+     "css/CSS2/text/bidi-span-002.html",
+     [
+      [
+       "/css/CSS2/text/bidi-span-002-ref.html",
+       "=="
+      ]
+     ],
+     {}
+    ]
+   ],
    "css/CSS2/text/letter-spacing-004.xht": [
     [
      "css/CSS2/text/letter-spacing-004.xht",
@@ -134173,6 +134209,18 @@
      {}
     ]
    ],
+   "css/css-multicol/multicol-span-all-children-height-008.html": [
+    [
+     "css/css-multicol/multicol-span-all-children-height-008.html",
+     [
+      [
+       "/css/css-multicol/multicol-span-all-children-height-008-ref.html",
+       "=="
+      ]
+     ],
+     {}
+    ]
+   ],
    "css/css-multicol/multicol-span-all-dynamic-add-001.html": [
     [
      "css/css-multicol/multicol-span-all-dynamic-add-001.html",
@@ -135169,6 +135217,18 @@
      {}
     ]
    ],
+   "css/css-overflow/float-with-relpos-and-transform.html": [
+    [
+     "css/css-overflow/float-with-relpos-and-transform.html",
+     [
+      [
+       "/css/reference/ref-filled-green-100px-square-only.html",
+       "=="
+      ]
+     ],
+     {}
+    ]
+   ],
    "css/css-overflow/input-scrollable-region-001.html": [
     [
      "css/css-overflow/input-scrollable-region-001.html",
@@ -135805,6 +135865,18 @@
      {}
     ]
    ],
+   "css/css-paint-api/geometry-border-image-005.https.html": [
+    [
+     "css/css-paint-api/geometry-border-image-005.https.html",
+     [
+      [
+       "/css/css-paint-api/geometry-border-image-005-ref.html",
+       "=="
+      ]
+     ],
+     {}
+    ]
+   ],
    "css/css-paint-api/geometry-with-float-size.https.html": [
     [
      "css/css-paint-api/geometry-with-float-size.https.html",
@@ -239595,6 +239667,12 @@
    "css/CSS2/tables/table-vertical-align-baseline-001-ref.xht": [
     []
    ],
+   "css/CSS2/text/bidi-span-001-ref.html": [
+    []
+   ],
+   "css/CSS2/text/bidi-span-002-ref.html": [
+    []
+   ],
    "css/CSS2/text/letter-spacing-004-ref.xht": [
     []
    ],
@@ -251436,6 +251514,9 @@
    "css/css-multicol/multicol-span-all-children-height-007-ref.html": [
     []
    ],
+   "css/css-multicol/multicol-span-all-children-height-008-ref.html": [
+    []
+   ],
    "css/css-multicol/multicol-span-all-dynamic-add-001-ref.html": [
     []
    ],
@@ -251991,6 +252072,9 @@
    "css/css-paint-api/geometry-border-image-004-ref.html": [
     []
    ],
+   "css/css-paint-api/geometry-border-image-005-ref.html": [
+    []
+   ],
    "css/css-paint-api/geometry-with-float-size-ref.html": [
     []
    ],
@@ -280056,6 +280140,9 @@
    "service-workers/service-worker/resources/fetch-csp-iframe.html.sub.headers": [
     []
    ],
+   "service-workers/service-worker/resources/fetch-event-add-async-worker.js": [
+    []
+   ],
    "service-workers/service-worker/resources/fetch-event-after-navigation-within-page-iframe.html": [
     []
    ],
@@ -292772,6 +292859,12 @@
      {}
     ]
    ],
+   "2dcontext/imagebitmap/createImageBitmap-serializable.html": [
+    [
+     "2dcontext/imagebitmap/createImageBitmap-serializable.html",
+     {}
+    ]
+   ],
    "2dcontext/imagebitmap/createImageBitmap-sizeOverflow.html": [
     [
      "2dcontext/imagebitmap/createImageBitmap-sizeOverflow.html",
@@ -308579,6 +308672,12 @@
      }
     ]
    ],
+   "compat/webkit-box-removing-triggering-anonymous-merge.html": [
+    [
+     "compat/webkit-box-removing-triggering-anonymous-merge.html",
+     {}
+    ]
+   ],
    "compat/webkit-gradient-comma.html": [
     [
      "compat/webkit-gradient-comma.html",
@@ -319597,6 +319696,12 @@
      {}
     ]
    ],
+   "css/css-masking/animations/clip-interpolation.html": [
+    [
+     "css/css-masking/animations/clip-interpolation.html",
+     {}
+    ]
+   ],
    "css/css-masking/animations/clip-path-interpolation.html": [
     [
      "css/css-masking/animations/clip-path-interpolation.html",
@@ -319699,6 +319804,12 @@
      {}
     ]
    ],
+   "css/css-masking/parsing/mask-invalid.html": [
+    [
+     "css/css-masking/parsing/mask-invalid.html",
+     {}
+    ]
+   ],
    "css/css-masking/parsing/mask-position-invalid.html": [
     [
      "css/css-masking/parsing/mask-position-invalid.html",
@@ -319729,6 +319840,12 @@
      {}
     ]
    ],
+   "css/css-masking/parsing/mask-valid.sub.html": [
+    [
+     "css/css-masking/parsing/mask-valid.sub.html",
+     {}
+    ]
+   ],
    "css/css-multicol/abspos-in-multicol-with-spanner-crash.html": [
     [
      "css/css-multicol/abspos-in-multicol-with-spanner-crash.html",
@@ -367623,6 +367740,12 @@
      {}
     ]
    ],
+   "mediacapture-record/MediaRecorder-bitrate.https.html": [
+    [
+     "mediacapture-record/MediaRecorder-bitrate.https.html",
+     {}
+    ]
+   ],
    "mediacapture-record/MediaRecorder-creation.https.html": [
     [
      "mediacapture-record/MediaRecorder-creation.https.html",
@@ -367659,6 +367782,12 @@
      {}
     ]
    ],
+   "mediacapture-record/MediaRecorder-mimetype.html": [
+    [
+     "mediacapture-record/MediaRecorder-mimetype.html",
+     {}
+    ]
+   ],
    "mediacapture-record/MediaRecorder-pause-resume.html": [
     [
      "mediacapture-record/MediaRecorder-pause-resume.html",
@@ -397429,6 +397558,12 @@
      {}
     ]
    ],
+   "service-workers/service-worker/fetch-event-add-async.https.html": [
+    [
+     "service-workers/service-worker/fetch-event-add-async.https.html",
+     {}
+    ]
+   ],
    "service-workers/service-worker/fetch-event-after-navigation-within-page.https.html": [
     [
      "service-workers/service-worker/fetch-event-after-navigation-within-page.https.html",
@@ -412852,6 +412987,24 @@
      }
     ]
    ],
+   "webaudio/the-audio-api/processing-model/cycle-witout-delay.html": [
+    [
+     "webaudio/the-audio-api/processing-model/cycle-witout-delay.html",
+     {}
+    ]
+   ],
+   "webaudio/the-audio-api/processing-model/delay-time-clamping.html": [
+    [
+     "webaudio/the-audio-api/processing-model/delay-time-clamping.html",
+     {}
+    ]
+   ],
+   "webaudio/the-audio-api/processing-model/feedback-delay-time.html": [
+    [
+     "webaudio/the-audio-api/processing-model/feedback-delay-time.html",
+     {}
+    ]
+   ],
    "webaudio/the-audio-api/the-analysernode-interface/ctor-analyser.html": [
     [
      "webaudio/the-audio-api/the-analysernode-interface/ctor-analyser.html",
@@ -446890,7 +447043,7 @@
    "support"
   ],
   ".taskcluster.yml": [
-   "b23cc93e633021686192b5cc1acbb7d8b6b3fe96",
+   "adb81d6c0271ac5d8061782eac1b3e181984eb68",
    "support"
   ],
   ".well-known/README.md": [
@@ -449393,6 +449546,10 @@
    "9f19f6ae66b58f93c23ba8aeb095838d9a6cc5c9",
    "testharness"
   ],
+  "2dcontext/imagebitmap/createImageBitmap-serializable.html": [
+   "44e7a40351080d47675edb426f78cec4fa795920",
+   "testharness"
+  ],
   "2dcontext/imagebitmap/createImageBitmap-sizeOverflow.html": [
    "f58825cc371f04bf186ba23fa869391f3d2d3f6c",
    "testharness"
@@ -458602,7 +458759,7 @@
    "support"
   ],
   "common/security-features/resources/common.sub.js": [
-   "12776b1a4b55dc76415ea63abc4a93dab2fedd2a",
+   "c974e83b9604d5770ffb849a1b77f963d3f7955b",
    "support"
   ],
   "common/security-features/resources/common.sub.js.headers": [
@@ -458825,6 +458982,10 @@
    "06e728342cdb63a72b420423b40b6e32ae3e2162",
    "reftest"
   ],
+  "compat/webkit-box-removing-triggering-anonymous-merge.html": [
+   "8506425548b6ff97491e388dc1a1f3830aa790fc",
+   "testharness"
+  ],
   "compat/webkit-gradient-comma.html": [
    "b288a9a43fe8eba26a4ef37bd5439cbe75047885",
    "testharness"
@@ -476510,7 +476671,7 @@
    "testharness"
   ],
   "contacts/contacts-select.https.window.js": [
-   "8d1fdfbfdff539e7dd17da4b0e28ef01ae47a2d5",
+   "5503ea6968a8d2bd89e49a67bf0def695738d68d",
    "testharness"
   ],
   "contacts/resources/helpers.js": [
@@ -501105,6 +501266,10 @@
    "59843ae54b64f6ce4f7e616d4be491c911ea84cf",
    "support"
   ],
+  "css/CSS2/floats/adjoining-floats-dynamic.html": [
+   "3446d972d72ec8832ab8ac320a84dff609676ae3",
+   "reftest"
+  ],
   "css/CSS2/floats/computed-float-position-absolute.html": [
    "ad9220b3a06085c458f7100c896100fb32f562e8",
    "testharness"
@@ -531953,6 +532118,22 @@
    "ad267c450014629fbd309ed6825d94379d2fe882",
    "visual"
   ],
+  "css/CSS2/text/bidi-span-001-ref.html": [
+   "594847b128522adae1b7b49dbe739b00012feb9b",
+   "support"
+  ],
+  "css/CSS2/text/bidi-span-001.html": [
+   "b645a2b548c46b064b1a5f3012240a3947c772b9",
+   "reftest"
+  ],
+  "css/CSS2/text/bidi-span-002-ref.html": [
+   "6cc72c208a994a9e6ee99aac23689d3567e3a465",
+   "support"
+  ],
+  "css/CSS2/text/bidi-span-002.html": [
+   "d4fc6de070d23ebe8817e9a299c44e48cad256a9",
+   "reftest"
+  ],
   "css/CSS2/text/bidi-text-decoration-underline-001.xht": [
    "e3efb521f2208113ad3278a261348bc5997240f5",
    "visual"
@@ -568461,6 +568642,10 @@
    "7f92755b092845d3d550568e0572453801451f3d",
    "support"
   ],
+  "css/css-masking/animations/clip-interpolation.html": [
+   "322ebd724e8524e85d8afe369b6bafaabbec8c79",
+   "testharness"
+  ],
   "css/css-masking/animations/clip-path-interpolation.html": [
    "21c34f1f2b75ec7345a97b00db62a49b038cf026",
    "testharness"
@@ -569481,6 +569666,10 @@
    "d60802b897fedab122fb4661f312bd5358785570",
    "testharness"
   ],
+  "css/css-masking/parsing/mask-invalid.html": [
+   "367049cf19ffc2390316470dec3d789fbbee36a8",
+   "testharness"
+  ],
   "css/css-masking/parsing/mask-position-invalid.html": [
    "c246a1e795eea6a9e31fe1155d55ceb8532d6032",
    "testharness"
@@ -569501,6 +569690,10 @@
    "31a528381af7d0bb3b4d1a30e1b3f20a0f2787ce",
    "testharness"
   ],
+  "css/css-masking/parsing/mask-valid.sub.html": [
+   "63aed3e33c46bdbf2c1bf8c8b8758daff7ab0bee",
+   "testharness"
+  ],
   "css/css-masking/test-mask-ref.html": [
    "938235acbd36309fb969c55f161239bcd5ab969e",
    "support"
@@ -570638,11 +570831,11 @@
    "reftest"
   ],
   "css/css-multicol/multicol-span-all-children-height-006-ref.html": [
-   "85dfa522c7de9152020342ddb67484b7f1e6977b",
+   "261ff480c38c70e5bf99b9886919088647fbef9e",
    "support"
   ],
   "css/css-multicol/multicol-span-all-children-height-006.html": [
-   "479fb2d0ced056f24b39126fa29574a6a811f8e6",
+   "5c1e634c2b2c25684eb55d58a5e4c8b7ca9de7ae",
    "reftest"
   ],
   "css/css-multicol/multicol-span-all-children-height-007-ref.html": [
@@ -570653,6 +570846,14 @@
    "80f34b45ded8af29c0600a6fa78584cb22b342fc",
    "reftest"
   ],
+  "css/css-multicol/multicol-span-all-children-height-008-ref.html": [
+   "80d783283fb7a6b02bac081cf9fcfe0017e9550b",
+   "support"
+  ],
+  "css/css-multicol/multicol-span-all-children-height-008.html": [
+   "0d7bd183841d5d4e55380d157461c9a8b9378a62",
+   "reftest"
+  ],
   "css/css-multicol/multicol-span-all-dynamic-add-001-ref.html": [
    "9f76ea15a0daa7753e76ad9b9a99948988c702d3",
    "support"
@@ -571501,6 +571702,10 @@
    "b9ba7acd150e5022de5c5208cd7f5f7d4dde93c3",
    "support"
   ],
+  "css/css-overflow/float-with-relpos-and-transform.html": [
+   "6024b7261750e0c5dc4a681dccee2ab72b83abca",
+   "reftest"
+  ],
   "css/css-overflow/inheritance.html": [
    "976406be413b9bdc8cef4acab0a0cd29df2dd43d",
    "testharness"
@@ -572253,6 +572458,14 @@
    "0f483cd5d19acf4923e60a9f59f55b2bd1e2d0d0",
    "reftest"
   ],
+  "css/css-paint-api/geometry-border-image-005-ref.html": [
+   "16d230411349ff25e2064fdc2eadd8992769dfa7",
+   "support"
+  ],
+  "css/css-paint-api/geometry-border-image-005.https.html": [
+   "efdd7fdf1b9673657b8a60bfa5851ff694489d87",
+   "reftest"
+  ],
   "css/css-paint-api/geometry-with-float-size-ref.html": [
    "c24a9d7bc0d9dd251186faec68d5bacb15db8c77",
    "support"
@@ -573018,7 +573231,7 @@
    "testharness"
   ],
   "css/css-position/position-absolute-replaced-minmax.html": [
-   "a5c0d516472b9a2a1be4d391f38cac412e6aa7d1",
+   "00780d650fae639b37f4e82eabcd77794eb1aae2",
    "testharness"
   ],
   "css/css-position/position-fixed-at-bottom-right-on-viewport.html": [
@@ -620310,7 +620523,7 @@
    "support"
   ],
   "docs/running-tests/webkitgtk_minibrowser.md": [
-   "b12859bcca9e6e90998735c97932c42d60aecba4",
+   "7aac81e5fce660db84969f9c0a7cae429a257207",
    "support"
   ],
   "docs/test-suite-design.md": [
@@ -633606,7 +633819,7 @@
    "testharness"
   ],
   "html/dom/idlharness.https.html": [
-   "0d3f1160d2819601afb2168bc15bfeeaddfed6f1",
+   "33ad5c6f6169a7e376aaadeba1b8df4dd6815f7c",
    "testharness"
   ],
   "html/dom/idlharness.worker.js": [
@@ -650642,7 +650855,7 @@
    "support"
   ],
   "interfaces/feature-policy.idl": [
-   "85601321a17f3d0a46d2246642d59ef44d916398",
+   "6f0d69fc378d91a1ededf21b273216061099c278",
    "support"
   ],
   "interfaces/fetch.idl": [
@@ -650998,7 +651211,7 @@
    "support"
   ],
   "interfaces/webrtc-stats.idl": [
-   "e41d7357b1a20328cd543c118005f2d9f77f0773",
+   "2b823047ff1e37a13e9d2e71711360944019fcb5",
    "support"
   ],
   "interfaces/webrtc.idl": [
@@ -652178,11 +652391,11 @@
    "reftest"
   ],
   "mathml/presentation-markup/menclose/legacy-menclose-radical-notation-ref.html": [
-   "f0b5bdd9f04e795400f2741b47ebb82d0d3a61cb",
+   "c67ac03f5dcc90d24b15ae89c269c99bb75e2c48",
    "support"
   ],
   "mathml/presentation-markup/menclose/legacy-menclose-radical-notation.html": [
-   "d7f0627059ad9e400480d574b5e83cff9113b107",
+   "9b71389e74dd1125135aa69fc3c8a47122d7a4a8",
    "reftest"
   ],
   "mathml/presentation-markup/mrow/inferred-mrow-baseline.html": [
@@ -652998,7 +653211,7 @@
    "reftest"
   ],
   "mathml/relations/html5-tree/tabindex-001.html": [
-   "aaf82f77caa87cadd4dfa4706a2bc15192006a6a",
+   "8f8536881416584656277eeaaed4604b7f6def4d",
    "testharness"
   ],
   "mathml/relations/html5-tree/tabindex-002.html": [
@@ -653937,8 +654150,12 @@
    "d59e5e30845eaef12bab6419e348a01779313c56",
    "support"
   ],
+  "mediacapture-record/MediaRecorder-bitrate.https.html": [
+   "472c0661cb7b5981b2de671458e2da3592516d0c",
+   "testharness"
+  ],
   "mediacapture-record/MediaRecorder-creation.https.html": [
-   "419211c9dcf63241b63cd11d671a0800b3998d83",
+   "b724ca14503a87ab06eb5e12c469fccd3dd3fde9",
    "testharness"
   ],
   "mediacapture-record/MediaRecorder-destroy-script-execution.html": [
@@ -653958,11 +654175,15 @@
    "testharness"
   ],
   "mediacapture-record/MediaRecorder-events-and-exceptions.html": [
-   "58b9c08ecab0ff8872748f5215743379876ea5ef",
+   "cddc07e5079481e0ac7b44d1c223d88bea9e64fe",
+   "testharness"
+  ],
+  "mediacapture-record/MediaRecorder-mimetype.html": [
+   "ddc56e9cb750c59753e238c8ec39c6e1f128790b",
    "testharness"
   ],
   "mediacapture-record/MediaRecorder-pause-resume.html": [
-   "39a8883664550af1a48ae965d4789a0d6df97d28",
+   "33dfd8560c04d9e9de335b13cfcb33428a6b7e24",
    "testharness"
   ],
   "mediacapture-record/MediaRecorder-stop.html": [
@@ -653970,7 +654191,7 @@
    "testharness"
   ],
   "mediacapture-record/idlharness.window.js": [
-   "86f5a158822156b54e776639fb9c7504f0ff7498",
+   "2e304b0a0e6ece247614c5c692ef0e368f5ad216",
    "testharness"
   ],
   "mediacapture-record/support/MediaRecorder-iframe.html": [
@@ -677394,7 +677615,7 @@
    "support"
   ],
   "resources/chromium/webxr-test.js": [
-   "df91abf6d7f2c2cb10dfd5798f27a7d96a6ad339",
+   "94031657b4b6d2698739eddf0bd4028e0aa8fdea",
    "support"
   ],
   "resources/chromium/webxr-test.js.headers": [
@@ -679513,6 +679734,10 @@
    "4f176220d6100c4efb1bfda817b84cf5f53a4f3d",
    "testharness"
   ],
+  "service-workers/service-worker/fetch-event-add-async.https.html": [
+   "ac13e4f41675c22669862751b9209835d7210231",
+   "testharness"
+  ],
   "service-workers/service-worker/fetch-event-after-navigation-within-page.https.html": [
    "4812d8a91551edae84b5e2805804fc9d8899f3e9",
    "testharness"
@@ -679678,7 +679903,7 @@
    "testharness"
   ],
   "service-workers/service-worker/global-serviceworker.https.any.js": [
-   "489b37f83e1c21809e9b0b63d0f0e59db23d197c",
+   "2335f635b2e6ad50b2d1bf4117eb08b19d3ac3b1",
    "testharness"
   ],
   "service-workers/service-worker/http-to-https-redirect-and-register.https.html": [
@@ -680349,6 +680574,10 @@
    "300efe049b5de8810f7c44863e11c280ca2926f3",
    "support"
   ],
+  "service-workers/service-worker/resources/fetch-event-add-async-worker.js": [
+   "a5a44a57c99cb3a289f0015168609852729d50a5",
+   "support"
+  ],
   "service-workers/service-worker/resources/fetch-event-after-navigation-within-page-iframe.html": [
    "bf8a6d5ce51facdd65f30ce5750417c7fcf2ef02",
    "support"
@@ -688198,7 +688427,7 @@
    "support"
   ],
   "tools/ci/run_tc.py": [
-   "b2826bf075e9b1e82ee3d021003134930231f556",
+   "3201ff3a9d309719da2fe038c73d1b144ffdb5d2",
    "support"
   ],
   "tools/ci/taskcluster-run.py": [
@@ -688234,11 +688463,11 @@
    "support"
   ],
   "tools/docker/Dockerfile.webkitgtk": [
-   "8d792b36a473059c41d9e68789bab7ba8a7c2855",
+   "58080def60ff4f26277c96015a8c2968254907f3",
    "support"
   ],
   "tools/docker/README.md": [
-   "c444e4a957fd0ba55e0d51a0e87b9562550e0add",
+   "6bcc47c7744e4cc8be96b1c9590878955080da27",
    "support"
   ],
   "tools/docker/__init__.py": [
@@ -693310,7 +693539,7 @@
    "support"
   ],
   "tools/wptrunner/wptrunner/browsers/base.py": [
-   "08b5880a1b7e903fb2ca937d7f3aef43fc44b2f6",
+   "d17229da4686548e05c228a7345194e0d8f4d8dd",
    "support"
   ],
   "tools/wptrunner/wptrunner/browsers/chrome.py": [
@@ -693338,11 +693567,11 @@
    "support"
   ],
   "tools/wptrunner/wptrunner/browsers/epiphany.py": [
-   "599ec9f3110f89f5d64effe98130ede930f1fb7c",
+   "37e2f21421ae54e0c2a6b11cb0763d65b5f3ea72",
    "support"
   ],
   "tools/wptrunner/wptrunner/browsers/firefox.py": [
-   "290fcff5ab22bd5ca19cedb4d3f38f5b8197768f",
+   "1763ff44b4e55c14c8f5d753defb3ba39e017262",
    "support"
   ],
   "tools/wptrunner/wptrunner/browsers/firefox_android.py": [
@@ -693386,7 +693615,7 @@
    "support"
   ],
   "tools/wptrunner/wptrunner/browsers/webkitgtk_minibrowser.py": [
-   "65f78125ad7a89d43c08b6986bf41145cc71d04c",
+   "3c4947335bf32fd64c5c539dc08b851106c2f254",
    "support"
   ],
   "tools/wptrunner/wptrunner/config.py": [
@@ -697405,6 +697634,18 @@
    "2778493e3b6c12d4c00c77bd975e845063621522",
    "support"
   ],
+  "webaudio/the-audio-api/processing-model/cycle-witout-delay.html": [
+   "ed26ad2ced2c226d3388f1941653f921f6d93656",
+   "testharness"
+  ],
+  "webaudio/the-audio-api/processing-model/delay-time-clamping.html": [
+   "3f8ed24429a7c4532610c7a42e366dc3aff0c7d6",
+   "testharness"
+  ],
+  "webaudio/the-audio-api/processing-model/feedback-delay-time.html": [
+   "50c8e455b908af3bcb42b4fcfda157d54b9f9abe",
+   "testharness"
+  ],
   "webaudio/the-audio-api/the-analysernode-interface/.gitkeep": [
    "e69de29bb2d1d6434b8b29ae775ad8c2e48c5391",
    "support"
diff --git a/tests/wpt/metadata/css/compositing/mix-blend-mode/mix-blend-mode-animation.html.ini b/tests/wpt/metadata/css/compositing/mix-blend-mode/mix-blend-mode-animation.html.ini
new file mode 100644
index 00000000000..5496474410b
--- /dev/null
+++ b/tests/wpt/metadata/css/compositing/mix-blend-mode/mix-blend-mode-animation.html.ini
@@ -0,0 +1,2 @@
+[mix-blend-mode-animation.html]
+  expected: FAIL
diff --git a/tests/wpt/metadata/css/css-transforms/animation/perspective-interpolation.html.ini b/tests/wpt/metadata/css/css-transforms/animation/perspective-interpolation.html.ini
index 03f2f3fe9d1..c511d92d674 100644
--- a/tests/wpt/metadata/css/css-transforms/animation/perspective-interpolation.html.ini
+++ b/tests/wpt/metadata/css/css-transforms/animation/perspective-interpolation.html.ini
@@ -1,5 +1,4 @@
 [perspective-interpolation.html]
-  expected: CRASH
   [ perspective interpolation]
     expected: FAIL
 
diff --git a/tests/wpt/metadata/dom/nodes/Document-contentType/contentType/contenttype_txt.html.ini b/tests/wpt/metadata/dom/nodes/Document-contentType/contentType/contenttype_txt.html.ini
deleted file mode 100644
index c3916f8555d..00000000000
--- a/tests/wpt/metadata/dom/nodes/Document-contentType/contentType/contenttype_txt.html.ini
+++ /dev/null
@@ -1,2 +0,0 @@
-[contenttype_txt.html]
-  expected: CRASH
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 9aa8d1390da..6960c088389 100644
--- a/tests/wpt/metadata/fetch/content-type/response.window.js.ini
+++ b/tests/wpt/metadata/fetch/content-type/response.window.js.ini
@@ -312,15 +312,9 @@
   [<iframe>: separate response Content-Type: */* text/html]
     expected: FAIL
 
-  [<iframe>: combined response Content-Type: text/html */*]
+  [<iframe>: separate response Content-Type: text/html;" text/plain]
     expected: FAIL
 
-  [<iframe>: separate response Content-Type: text/html */*;charset=gbk]
-    expected: FAIL
-
-  [<iframe>: separate response Content-Type: text/html;" \\" text/plain]
-    expected: FAIL
-
-  [<iframe>: combined response Content-Type: text/html */*;charset=gbk]
+  [<iframe>: combined response Content-Type: text/html;x=" text/plain]
     expected: FAIL
 
diff --git a/tests/wpt/metadata/fetch/content-type/script.window.js.ini b/tests/wpt/metadata/fetch/content-type/script.window.js.ini
index c7413d589dc..c0374f76e40 100644
--- a/tests/wpt/metadata/fetch/content-type/script.window.js.ini
+++ b/tests/wpt/metadata/fetch/content-type/script.window.js.ini
@@ -56,9 +56,9 @@
   [separate text/javascript x/x]
     expected: FAIL
 
-  [separate text/javascript;charset=windows-1252 error text/javascript]
+  [separate text/javascript error]
     expected: FAIL
 
-  [separate text/javascript;charset=windows-1252  text/javascript]
+  [separate text/javascript ]
     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 b2cd43ef76c..536384f36e1 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 +11,6 @@
   [X-Content-Type-Options%3A%20nosniff%0C]
     expected: FAIL
 
-  [X-Content-Type-Options%3A%20'NosniFF']
-    expected: FAIL
-
-  [X-Content-Type-Options%3A%0D%0AX-Content-Type-Options%3A%20nosniff]
+  [X-Content-Type-Options%3A%20%2Cnosniff]
     expected: FAIL
 
diff --git a/tests/wpt/metadata/html/dom/idlharness.https.html.ini b/tests/wpt/metadata/html/dom/idlharness.https.html.ini
index 76078aa9780..a9257cabc65 100644
--- a/tests/wpt/metadata/html/dom/idlharness.https.html.ini
+++ b/tests/wpt/metadata/html/dom/idlharness.https.html.ini
@@ -764,9 +764,6 @@
   [OffscreenCanvasRenderingContext2D interface: attribute miterLimit]
     expected: FAIL
 
-  [MessageEvent interface: new MessageEvent("message", { data: 5 }) must inherit property "source" with the proper type]
-    expected: FAIL
-
   [Path2D interface: existence and properties of interface prototype object's @@unscopables property]
     expected: FAIL
 
@@ -1585,9 +1582,6 @@
   [Window interface: operation prompt(DOMString, DOMString)]
     expected: FAIL
 
-  [Window interface: window must inherit property "self" with the proper type]
-    expected: FAIL
-
   [Document interface: documentWithHandlers must inherit property "dir" with the proper type]
     expected: FAIL
 
@@ -1660,9 +1654,6 @@
   [Window interface: window must inherit property "onauxclick" with the proper type]
     expected: FAIL
 
-  [Window interface: window must inherit property "parent" with the proper type]
-    expected: FAIL
-
   [Window interface: calling createImageBitmap(ImageBitmapSource, long, long, long, long, ImageBitmapOptions) on window with too few arguments must throw TypeError]
     expected: FAIL
 
@@ -1672,9 +1663,6 @@
   [Document interface: new Document() must inherit property "queryCommandState(DOMString)" with the proper type]
     expected: FAIL
 
-  [Window interface: window must inherit property "frames" with the proper type]
-    expected: FAIL
-
   [Window interface: window must inherit property "onformdata" with the proper type]
     expected: FAIL
 
@@ -1747,9 +1735,6 @@
   [Document interface: new Document() must inherit property "alinkColor" with the proper type]
     expected: FAIL
 
-  [Document interface: iframe.contentDocument must inherit property "defaultView" with the proper type]
-    expected: FAIL
-
   [Document interface: new Document() must inherit property "queryCommandEnabled(DOMString)" with the proper type]
     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 e440b1e38c6..dc856a3d5a3 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
@@ -1,6 +1,5 @@
 [iframe_sandbox_popups_nonescaping-3.html]
   type: testharness
-  expected: TIMEOUT
   [Check that popups from a sandboxed iframe do not escape the sandbox]
-    expected: NOTRUN
+    expected: FAIL
 
diff --git a/tests/wpt/metadata/html/semantics/forms/autofocus/skip-document-with-fragment.html.ini b/tests/wpt/metadata/html/semantics/forms/autofocus/skip-document-with-fragment.html.ini
index 6852d7663de..c12c0f8ae48 100644
--- a/tests/wpt/metadata/html/semantics/forms/autofocus/skip-document-with-fragment.html.ini
+++ b/tests/wpt/metadata/html/semantics/forms/autofocus/skip-document-with-fragment.html.ini
@@ -1,8 +1,4 @@
 [skip-document-with-fragment.html]
-  expected: TIMEOUT
   [Autofocus elements in iframed documents with URL fragments should be skipped.]
     expected: FAIL
 
-  [Autofocus elements in top-level browsing context's documents with URI fragments should be skipped.]
-    expected: TIMEOUT
-
diff --git a/tests/wpt/metadata/html/semantics/interactive-elements/the-details-element/toggleEvent.html.ini b/tests/wpt/metadata/html/semantics/interactive-elements/the-details-element/toggleEvent.html.ini
new file mode 100644
index 00000000000..9e522297c94
--- /dev/null
+++ b/tests/wpt/metadata/html/semantics/interactive-elements/the-details-element/toggleEvent.html.ini
@@ -0,0 +1,7 @@
+[toggleEvent.html]
+  [Calling open twice on 'details' fires only one toggle event]
+    expected: FAIL
+
+  [Setting open=true to opened 'details' element should not fire a toggle event at the 'details' element]
+    expected: FAIL
+
diff --git a/tests/wpt/metadata/resource-timing/nested-context-navigations-iframe.html.ini b/tests/wpt/metadata/resource-timing/nested-context-navigations-iframe.html.ini
index ec371a1bf72..8594361ff44 100644
--- a/tests/wpt/metadata/resource-timing/nested-context-navigations-iframe.html.ini
+++ b/tests/wpt/metadata/resource-timing/nested-context-navigations-iframe.html.ini
@@ -1,5 +1,5 @@
 [nested-context-navigations-iframe.html]
-  expected: TIMEOUT
+  expected: CRASH
   [Test that iframe navigations are not observable by the parent, even after history navigations by the parent]
     expected: FAIL
 
diff --git a/tests/wpt/metadata/webaudio/the-audio-api/processing-model/delay-time-clamping.html.ini b/tests/wpt/metadata/webaudio/the-audio-api/processing-model/delay-time-clamping.html.ini
new file mode 100644
index 00000000000..34175cfb5a9
--- /dev/null
+++ b/tests/wpt/metadata/webaudio/the-audio-api/processing-model/delay-time-clamping.html.ini
@@ -0,0 +1,4 @@
+[delay-time-clamping.html]
+  [Test that a DelayNode allows a feedback loop of a single rendering quantum]
+    expected: FAIL
+
diff --git a/tests/wpt/metadata/webaudio/the-audio-api/processing-model/feedback-delay-time.html.ini b/tests/wpt/metadata/webaudio/the-audio-api/processing-model/feedback-delay-time.html.ini
new file mode 100644
index 00000000000..18a7cd2f6b4
--- /dev/null
+++ b/tests/wpt/metadata/webaudio/the-audio-api/processing-model/feedback-delay-time.html.ini
@@ -0,0 +1,4 @@
+[feedback-delay-time.html]
+  [Test that a DelayNode allows a feedback loop of a single rendering quantum]
+    expected: FAIL
+
diff --git a/tests/wpt/metadata/webaudio/the-audio-api/the-analysernode-interface/realtimeanalyser-fft-scaling.html.ini b/tests/wpt/metadata/webaudio/the-audio-api/the-analysernode-interface/realtimeanalyser-fft-scaling.html.ini
index 66bd350083b..a56bad443a2 100644
--- a/tests/wpt/metadata/webaudio/the-audio-api/the-analysernode-interface/realtimeanalyser-fft-scaling.html.ini
+++ b/tests/wpt/metadata/webaudio/the-audio-api/the-analysernode-interface/realtimeanalyser-fft-scaling.html.ini
@@ -1,4 +1,5 @@
 [realtimeanalyser-fft-scaling.html]
+  expected: TIMEOUT
   [X 2048-point FFT peak position is not equal to 64. Got 0.]
     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/mozilla/meta/css/transition_calc_implicit.html.ini b/tests/wpt/mozilla/meta/css/transition_calc_implicit.html.ini
new file mode 100644
index 00000000000..dbea4f293ad
--- /dev/null
+++ b/tests/wpt/mozilla/meta/css/transition_calc_implicit.html.ini
@@ -0,0 +1,2 @@
+[transition_calc_implicit.html]
+  expected: TIMEOUT
diff --git a/tests/wpt/web-platform-tests/.taskcluster.yml b/tests/wpt/web-platform-tests/.taskcluster.yml
index b23cc93e633..adb81d6c027 100644
--- a/tests/wpt/web-platform-tests/.taskcluster.yml
+++ b/tests/wpt/web-platform-tests/.taskcluster.yml
@@ -12,15 +12,16 @@ tasks:
             $flatten:
               $match: {
                 event.ref == "refs/heads/master": [{name: firefox, channel: nightly}, {name: chrome, channel: dev}],
-                event.ref == "refs/heads/epochs/daily": [{name: firefox, channel: stable}, {name: chrome, channel: stable}],
+                event.ref == "refs/heads/epochs/daily": [{name: firefox, channel: stable}, {name: chrome, channel: stable}, {name: webkitgtk_minibrowser, channel: stable}],
                 event.ref == "refs/heads/epochs/weekly": [{name: firefox, channel: beta}, {name: chrome, channel: beta}],
                 event.ref == "refs/heads/triggers/chrome_stable": [{name: chrome, channel: stable}],
                 event.ref == "refs/heads/triggers/chrome_beta": [{name: chrome, channel: beta}],
                 event.ref == "refs/heads/triggers/chrome_dev": [{name: chrome, channel: dev}],
                 event.ref == "refs/heads/triggers/firefox_stable": [{name: firefox, channel: stable}],
                 event.ref == "refs/heads/triggers/firefox_beta": [{name: firefox, channel: beta}],
-                event.ref == "refs/heads/triggers/firefox_nightly": [{name: firefox, channel: nightly}]
-                }
+                event.ref == "refs/heads/triggers/firefox_nightly": [{name: firefox, channel: nightly}],
+                event.ref == "refs/heads/triggers/webkitgtk_minibrowser_stable": [{name: webkitgtk_minibrowser, channel: stable}]
+              }
           each(browser):
             $map:
               - [testharness, 1, 15]
@@ -70,7 +71,12 @@ tasks:
                 owner: ${event.pusher.email}
                 source: ${event.repository.url}
               payload:
-                image: harjgam/web-platform-tests:0.33
+                image:
+                  $if: browser.name == 'webkitgtk_minibrowser'
+                  then:
+                    cl0p3z/web-platform-tests:0.1
+                  else:
+                    harjgam/web-platform-tests:0.33
                 maxRunTime: 7200
                 artifacts:
                   public/results:
diff --git a/tests/wpt/web-platform-tests/2dcontext/imagebitmap/createImageBitmap-serializable.html b/tests/wpt/web-platform-tests/2dcontext/imagebitmap/createImageBitmap-serializable.html
new file mode 100644
index 00000000000..44e7a403510
--- /dev/null
+++ b/tests/wpt/web-platform-tests/2dcontext/imagebitmap/createImageBitmap-serializable.html
@@ -0,0 +1,42 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>createImageBitmap serialize test</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/namespaces.js"></script>
+<script src="common.sub.js"></script>
+<div id=log></div>
+<script>
+let worker, continuations = {};
+setup(function() {
+    worker = new Worker("transfer-worker.js");
+    worker.addEventListener("message", function(event) {
+        let { name, bitmap } = event.data;
+        if (continuations.hasOwnProperty(name)) {
+            continuations[name](bitmap);
+        }
+    });
+});
+
+for (let { name, factory } of imageSourceTypes) {
+    promise_test(function(t) {
+        return factory().then(createImageBitmap).then(function(bitmap) {
+            assert_equals(bitmap.width, 20);
+            assert_equals(bitmap.height, 20);
+
+            worker.postMessage({ name: t.name, bitmap: bitmap });
+
+            assert_equals(bitmap.width, 20);
+            assert_equals(bitmap.height, 20);
+
+            return new Promise(function(resolve) {
+                continuations[t.name] = resolve;
+            });
+        }).then(function(bitmap) {
+            assert_class_string(bitmap, "ImageBitmap");
+            assert_equals(bitmap.width, 20);
+            assert_equals(bitmap.height, 20);
+        });
+    }, `Serialize ImageBitmap created from ${name}`);
+}
+</script>
diff --git a/tests/wpt/web-platform-tests/common/security-features/resources/common.sub.js b/tests/wpt/web-platform-tests/common/security-features/resources/common.sub.js
index 12776b1a4b5..c974e83b960 100644
--- a/tests/wpt/web-platform-tests/common/security-features/resources/common.sub.js
+++ b/tests/wpt/web-platform-tests/common/security-features/resources/common.sub.js
@@ -1225,7 +1225,7 @@ function invokeFromIframe(subresource, sourceContextList) {
     promise = fetch(frameUrl)
       .then(r => r.text())
       .then(t => {
-          frameContnent = t;
+          frameContent = t;
           iframe = createElement("iframe", {}, document.body, true);
           return iframe.eventPromise;
         })
diff --git a/tests/wpt/web-platform-tests/compat/webkit-box-removing-triggering-anonymous-merge.html b/tests/wpt/web-platform-tests/compat/webkit-box-removing-triggering-anonymous-merge.html
new file mode 100644
index 00000000000..8506425548b
--- /dev/null
+++ b/tests/wpt/web-platform-tests/compat/webkit-box-removing-triggering-anonymous-merge.html
@@ -0,0 +1,14 @@
+<!DOCTYPE html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div style="display: -webkit-box">
+  <span><div></div></span>
+  <div id="target"></div>
+  text
+</div>
+<script>
+// Force a layout before removing.
+document.body.offsetTop;
+document.getElementById('target').remove();
+done();
+</script>
diff --git a/tests/wpt/web-platform-tests/contacts/contacts-select.https.window.js b/tests/wpt/web-platform-tests/contacts/contacts-select.https.window.js
index 8d1fdfbfdff..5503ea6968a 100644
--- a/tests/wpt/web-platform-tests/contacts/contacts-select.https.window.js
+++ b/tests/wpt/web-platform-tests/contacts/contacts-select.https.window.js
@@ -48,6 +48,17 @@ contactsTestWithUserActivation(async (test, setSelectedContacts) => {
 }, 'The Contact API can fail when the selector cannot be opened');
 
 contactsTestWithUserActivation(async (test, setSelectedContacts) => {
+  setSelectedContacts([]);
+
+  const properties = await navigator.contacts.getProperties();
+  assert_true(properties.length > 0);
+
+  // Requesting the available properties should not fail.
+  await navigator.contacts.select(properties);
+
+}, 'Supported contact properties are exposed.');
+
+contactsTestWithUserActivation(async (test, setSelectedContacts) => {
   // Returns two contacts with all information available.
   setSelectedContacts([
       { name: ['Dwight Schrute'], email: ['dwight@schrutefarmsbnb.com'], tel: ['000-0000'] },
diff --git a/tests/wpt/web-platform-tests/css/CSS2/floats/adjoining-floats-dynamic.html b/tests/wpt/web-platform-tests/css/CSS2/floats/adjoining-floats-dynamic.html
new file mode 100644
index 00000000000..3446d972d72
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/CSS2/floats/adjoining-floats-dynamic.html
@@ -0,0 +1,35 @@
+<!DOCTYPE html>
+<link rel="match" href="../../reference/ref-filled-green-100px-square.xht">
+<link rel="help" href="https://bugs.chromium.org/p/chromium/issues/detail?id=1003558">
+<style>
+#target {
+  height: 50px;
+  width: 0;
+  background: green;
+  float: right;
+}
+
+span {
+  float: left;
+  width: 50px;
+  height: 50px;
+  background: green;
+}
+</style>
+<p>Test passes if there is a filled green square and <strong>no red</strong>.</p>
+<div style="display: flow-root; width: 100px; background: red;">
+  <div id="target"></div>
+  <div style="position: absolute; width: 50px; height: 50px; background: green;"></div>
+  <div>
+    <div style="clear: both; height: 10px;">
+      <div>
+        <span></span>
+        <span></span>
+      </div>
+    </div>
+  </div>
+</div>
+<script>
+document.body.offsetTop;
+document.getElementById('target').style.width = '50px';
+</script>
diff --git a/tests/wpt/web-platform-tests/css/CSS2/text/bidi-span-001-ref.html b/tests/wpt/web-platform-tests/css/CSS2/text/bidi-span-001-ref.html
new file mode 100644
index 00000000000..594847b1285
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/CSS2/text/bidi-span-001-ref.html
@@ -0,0 +1,9 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<body>
+  <div>אבג</div>
+  <div>אבג</div>
+  <div>אבג</div>
+  <div>אבג</div>
+  <div>אבג</div>
+</body>
diff --git a/tests/wpt/web-platform-tests/css/CSS2/text/bidi-span-001.html b/tests/wpt/web-platform-tests/css/CSS2/text/bidi-span-001.html
new file mode 100644
index 00000000000..b645a2b548c
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/CSS2/text/bidi-span-001.html
@@ -0,0 +1,13 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Test: Inline boxes should not affect bidi reordering</title>
+<link rel="match" href="bidi-span-001-ref.html">
+<link rel="help" href="https://drafts.csswg.org/css2/visuren.html#direction">
+<link rel="author" title="Koji Ishii" href="mailto:kojii@chromium.org">
+<body>
+  <div>א<span></span>בג</div>
+  <div>א<span style="background: white"></span>בג</div>
+  <div>א<span>ב</span>ג</div>
+  <div>א<span style="background: white">ב</span>ג</div>
+  <div>אבג</div>
+</body>
diff --git a/tests/wpt/web-platform-tests/css/CSS2/text/bidi-span-002-ref.html b/tests/wpt/web-platform-tests/css/CSS2/text/bidi-span-002-ref.html
new file mode 100644
index 00000000000..6cc72c208a9
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/CSS2/text/bidi-span-002-ref.html
@@ -0,0 +1,2 @@
+<!DOCTYPE html>
+<body>()</body>
diff --git a/tests/wpt/web-platform-tests/css/CSS2/text/bidi-span-002.html b/tests/wpt/web-platform-tests/css/CSS2/text/bidi-span-002.html
new file mode 100644
index 00000000000..d4fc6de070d
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/CSS2/text/bidi-span-002.html
@@ -0,0 +1,24 @@
+<!DOCTYPE html>
+<title>CSS Test: Inline boxes should not affect bidi reordering</title>
+<link rel="match" href="bidi-span-002-ref.html">
+<link rel="help" href="https://drafts.csswg.org/css2/visuren.html#direction">
+<link rel="author" title="Koji Ishii" href="mailto:kojii@chromium.org">
+<style>
+body {
+  text-align: left;
+  direction: rtl;
+}
+
+.c1:before {
+  content: '(';
+}
+
+.c1:after {
+  content: ')';
+}
+
+.c2:after {
+  content: '';
+}
+</style>
+<body><span class="c1"><span class="c2"></span></span></body>
diff --git a/tests/wpt/web-platform-tests/css/css-masking/animations/clip-interpolation.html b/tests/wpt/web-platform-tests/css/css-masking/animations/clip-interpolation.html
new file mode 100644
index 00000000000..322ebd724e8
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-masking/animations/clip-interpolation.html
@@ -0,0 +1,117 @@
+<!DOCTYPE html>
+<meta charset="UTF-8">
+<title>clip interpolation</title>
+<link rel="help" href="https://drafts.fxtf.org/css-masking-1/#clip-property">
+<meta name="assert" content="clip supports animation">
+
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/css/support/interpolation-testcommon.js"></script>
+
+<style>
+.container {
+  width: 80px;
+  height: 80px;
+  background: black;
+  display: inline-block;
+  padding: 5px;
+}
+
+.container:nth-child(2n) {
+  background: green;
+}
+
+.parent {
+  clip: rect(100px, 0px, 100px, 0px);
+}
+
+.target {
+  width: 80px;
+  height: 80px;
+  display: inline-block;
+  position: absolute;
+  background: white;
+  clip: rect(0px, 100px, 0px, 100px);
+}
+</style>
+
+<body>
+<template id="target-template">
+<div class="container"><div class="target"></div></div>
+</template>
+<script>
+test_interpolation({
+  property: 'clip',
+  from: neutralKeyframe,
+  to: 'rect(20px, 20px, 20px, 20px)',
+}, [
+  {at: -1, expect: 'rect(-20px 180px -20px 180px)'},
+  {at: 0, expect: 'rect(0px 100px 0px 100px)'},
+  {at: 0.25, expect: 'rect(5px 80px 5px 80px)'},
+  {at: 0.75, expect: 'rect(15px 40px 15px 40px)'},
+  {at: 1, expect: 'rect(20px 20px 20px 20px)'},
+  {at: 2, expect: 'rect(40px -60px 40px -60px)'},
+]);
+
+test_no_interpolation({
+  property: 'clip',
+  from: 'initial',
+  to: 'rect(20px, 20px, 20px, 20px)',
+});
+
+test_interpolation({
+  property: 'clip',
+  from: 'inherit',
+  to: 'rect(20px, 20px, 20px, 20px)',
+}, [
+  {at: -1, expect: 'rect(180px -20px 180px -20px)'},
+  {at: 0, expect: 'rect(100px 0px 100px 0px)'},
+  {at: 0.25, expect: 'rect(80px 5px 80px 5px)'},
+  {at: 0.75, expect: 'rect(40px 15px 40px 15px)'},
+  {at: 1, expect: 'rect(20px 20px 20px 20px)'},
+  {at: 2, expect: 'rect(-60px 40px -60px 40px)'},
+]);
+
+test_no_interpolation({
+  property: 'clip',
+  from: 'unset',
+  to: 'rect(20px, 20px, 20px, 20px)',
+});
+
+test_interpolation({
+  property: 'clip',
+  from: 'rect(0px, 75px, 80px, 10px)',
+  to: 'rect(0px, 100px, 90px, 5px)'
+}, [
+  {at: -1, expect: 'rect(0px, 50px, 70px, 15px)'},
+  {at: 0, expect: 'rect(0px, 75px, 80px, 10px)'},
+  {at: 0.25, expect: 'rect(0px, 81.25px, 82.5px, 8.75px)'},
+  {at: 0.75, expect: 'rect(0px, 93.75px, 87.5px, 6.25px)'},
+  {at: 1, expect: 'rect(0px, 100px, 90px, 5px)'},
+  {at: 2, expect: 'rect(0px, 125px, 100px, 0px)'},
+]);
+
+test_no_interpolation({
+  property: 'clip',
+  from: 'rect(auto, auto, auto, 10px)',
+  to: 'rect(20px, 50px, 50px, auto)'
+});
+
+test_no_interpolation({
+  property: 'clip',
+  from: 'rect(auto, 0px, auto, 10px)',
+  to: 'rect(auto, 50px, 50px, auto)'
+});
+
+test_no_interpolation({
+  property: 'clip',
+  from: 'auto',
+  to: 'rect(0px, 50px, 50px, 0px)'
+});
+
+test_no_interpolation({
+  property: 'clip',
+  from: 'rect(0px, 50px, 50px, 0px)',
+  to: 'auto'
+});
+</script>
diff --git a/tests/wpt/web-platform-tests/css/css-masking/parsing/mask-invalid.html b/tests/wpt/web-platform-tests/css/css-masking/parsing/mask-invalid.html
new file mode 100644
index 00000000000..367049cf19f
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-masking/parsing/mask-invalid.html
@@ -0,0 +1,35 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8">
+<title>CSS Masking Module Level 1: parsing mask with invalid values</title>
+<link rel="help" href="https://www.w3.org/TR/css-masking-1/#the-mask">
+<meta name="assert" content="mask supports only the '<mask-layer>#' grammar.">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/css/support/parsing-testcommon.js"></script>
+</head>
+<body>
+<script>
+test_invalid_value('mask', 'none linear-gradient(to 0% 0%, rgb(0, 0, 0), rgb(0, 0, 255))');
+test_invalid_value('mask', 'none alpha luminance');
+test_invalid_value('mask', 'linear-gradient(to 0% 0%, rgb(0, 0, 0), rgb(0, 0, 255)) url("https://example.com/")');
+
+test_invalid_value('mask', '1px 2px 3px');
+test_invalid_value('mask', '1px 2px 3px 4px');
+test_invalid_value('mask', '1px 2px / contain / cover');
+
+test_invalid_value('mask', 'repeat-y repeat-x');
+
+test_invalid_value('mask', 'stroke-box no-clip view-box');
+
+test_invalid_value('mask', 'border-box view-box padding-box');
+
+test_invalid_value('mask', 'no-clip border-box content-box');
+
+test_invalid_value('mask', 'content-box stroke-box no-clip');
+
+test_invalid_value('mask', 'add intersect');
+</script>
+</body>
+</html>
diff --git a/tests/wpt/web-platform-tests/css/css-masking/parsing/mask-valid.sub.html b/tests/wpt/web-platform-tests/css/css-masking/parsing/mask-valid.sub.html
new file mode 100644
index 00000000000..63aed3e33c4
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-masking/parsing/mask-valid.sub.html
@@ -0,0 +1,62 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8">
+<title>CSS Masking Module Level 1: parsing mask with valid values</title>
+<link rel="help" href="https://www.w3.org/TR/css-masking-1/#the-mask">
+<meta name="assert" content="mask supports the full '<mask-layer>#' grammar.">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/css/support/parsing-testcommon.js"></script>
+</head>
+<body>
+<script>
+// <mask-layer> = <mask-reference> <masking-mode>? || <position> [ / <bg-size> ]? ||
+// <repeat-style> || <geometry-box> || [ <geometry-box> | no-clip ] || <compositing-operator>
+
+// <mask-reference> <masking-mode>?
+// <mask-reference> = none | <image> | <mask-source>
+// <masking-mode> = alpha | luminance | auto
+test_valid_value('mask', 'none');
+test_valid_value('mask', 'none alpha');
+test_valid_value('mask', 'linear-gradient(to left bottom, red, blue)');
+test_valid_value('mask', 'linear-gradient(to left bottom, red, blue) luminance');
+test_valid_value('mask', 'url("https://{{host}}/")');
+test_valid_value('mask', 'url("https://{{host}}/") alpha');
+
+// <position> [ / <bg-size> ]?
+test_valid_value('mask', 'linear-gradient(to left bottom, red, blue) 1px 2px');
+test_valid_value('mask', 'url("https://{{host}}/") 1px 2px / contain');
+
+// <repeat-style> = repeat-x | repeat-y | [repeat | space | round | no-repeat]{1,2}
+test_valid_value('mask', 'none repeat-y');
+
+// <geometry-box> = <shape-box> | fill-box | stroke-box | view-box
+// <shape-box> = <box> | margin-box
+// <box> = border-box | padding-box | content-box
+test_valid_value('mask', 'none border-box', 'none');
+test_valid_value('mask', 'linear-gradient(to left bottom, red, blue) padding-box');
+test_valid_value('mask', 'none content-box');
+test_valid_value('mask', 'none margin-box');
+test_valid_value('mask', 'url("https://{{host}}/") fill-box');
+test_valid_value('mask', 'linear-gradient(to left bottom, red, blue) stroke-box');
+test_valid_value('mask', 'none view-box');
+
+// [ <geometry-box> | no-clip ]
+test_valid_value('mask', 'none no-clip', 'none border-box no-clip');
+
+// <compositing-operator> = add | subtract | intersect | exclude
+test_valid_value('mask', 'url("https://{{host}}/") add', 'url("https://{{host}}/")');
+test_valid_value('mask', 'none subtract');
+test_valid_value('mask', 'url("https://{{host}}/") intersect');
+test_valid_value('mask', 'linear-gradient(to left bottom, red, blue) exclude');
+
+
+// <mask-layer> = <mask-reference> <masking-mode>? || <position> [ / <bg-size> ]? ||
+// <repeat-style> || <geometry-box> || [ <geometry-box> | no-clip ] || <compositing-operator>
+test_valid_value('mask', 'intersect no-clip space round 1px 2px / contain stroke-box linear-gradient(to left bottom, red, blue) luminance', 'linear-gradient(to left bottom, red, blue) luminance 1px 2px / contain space round stroke-box no-clip intersect');
+
+test_valid_value('mask', 'intersect no-clip space round 1px 2px / contain view-box, stroke-box linear-gradient(to left bottom, red, blue) luminance', 'none 1px 2px / contain space round view-box no-clip intersect, linear-gradient(to left bottom, red, blue) luminance stroke-box');
+</script>
+</body>
+</html>
diff --git a/tests/wpt/web-platform-tests/css/css-multicol/multicol-span-all-children-height-006-ref.html b/tests/wpt/web-platform-tests/css/css-multicol/multicol-span-all-children-height-006-ref.html
index 85dfa522c7d..261ff480c38 100644
--- a/tests/wpt/web-platform-tests/css/css-multicol/multicol-span-all-children-height-006-ref.html
+++ b/tests/wpt/web-platform-tests/css/css-multicol/multicol-span-all-children-height-006-ref.html
@@ -35,7 +35,7 @@
   </article>
   <div class="column-span">column-span1</div>
   <article>
-    <div class="container" style="border-top: none; height: 50px;">
+    <div class="container" style="border-top: none; height: 50px; margin-bottom: 1em;">
       <div class="block">block2</div>
     </div>
   </article>
diff --git a/tests/wpt/web-platform-tests/css/css-multicol/multicol-span-all-children-height-006.html b/tests/wpt/web-platform-tests/css/css-multicol/multicol-span-all-children-height-006.html
index 479fb2d0ced..5c1e634c2b2 100644
--- a/tests/wpt/web-platform-tests/css/css-multicol/multicol-span-all-children-height-006.html
+++ b/tests/wpt/web-platform-tests/css/css-multicol/multicol-span-all-children-height-006.html
@@ -19,6 +19,7 @@
     background-color: pink;
     border: 20px solid purple;
     margin-top: 1em;
+    margin-bottom: 1em;
   }
   div.block {
     width: 100px;
diff --git a/tests/wpt/web-platform-tests/css/css-multicol/multicol-span-all-children-height-008-ref.html b/tests/wpt/web-platform-tests/css/css-multicol/multicol-span-all-children-height-008-ref.html
new file mode 100644
index 00000000000..80d783283fb
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-multicol/multicol-span-all-children-height-008-ref.html
@@ -0,0 +1,49 @@
+<!DOCTYPE html>
+<html>
+  <meta charset="utf-8">
+  <title>CSS Multi-column Layout Test Reference: Test the borders drawing for a block split by column-span</title>
+  <link rel="author" title="Ting-Yu Lin" href="tlin@mozilla.com">
+  <link rel="author" title="Mozilla" href="https://www.mozilla.org/">
+
+  <style>
+  article {
+    column-count: 1;
+    column-fill: auto;
+    width: 200px;
+    background-color: lightgreen;
+  }
+  div.container {
+    height: auto;
+    background-color: pink;
+    border: 20px solid purple;
+  }
+  div.block {
+    width: 100px;
+    height: 100px;
+    background-color: yellow;
+  }
+  div.column-span {
+    width: 200px;
+    height: 50px;
+    background-color: lightblue;
+  }
+  </style>
+
+  <article>
+    <div class="container" style="border-bottom: 0;">
+      <div class="block">block1</div>
+    </div>
+  </article>
+  <div class="column-span">column-span1</div>
+  <article>
+    <div class="container" style="border-top: 0; border-bottom: 0;">
+      <div class="block">block2</div>
+    </div>
+  </article>
+  <div class="column-span">column-span2</div>
+  <article>
+    <div class="container" style="border-top: 0;">
+      <div class="block">block3</div>
+    </div>
+  </article>
+</html>
diff --git a/tests/wpt/web-platform-tests/css/css-multicol/multicol-span-all-children-height-008.html b/tests/wpt/web-platform-tests/css/css-multicol/multicol-span-all-children-height-008.html
new file mode 100644
index 00000000000..0d7bd183841
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-multicol/multicol-span-all-children-height-008.html
@@ -0,0 +1,46 @@
+<!DOCTYPE html>
+<html>
+  <meta charset="utf-8">
+  <title>CSS Multi-column Layout Test: Test the borders drawing for a block split by column-span</title>
+  <link rel="author" title="Ting-Yu Lin" href="tlin@mozilla.com">
+  <link rel="author" title="Mozilla" href="https://www.mozilla.org/">
+  <link rel="help" href="https://drafts.csswg.org/css-multicol-1/#column-span">
+  <link rel="match" href="multicol-span-all-children-height-008-ref.html">
+  <meta name="assert" content="This test verifies that the borders of block container with an auto block-size, split by column-span, are skipped on the sides adjacent to column-span.">
+
+  <!-- This test is adapted from multicol-span-all-children-height-005. -->
+
+  <style>
+  article {
+    column-count: 1;
+    column-fill: auto;
+    width: 200px;
+    background-color: lightgreen;
+  }
+  div.container {
+    height: auto;
+    border: 20px solid purple;
+    background-color: pink;
+  }
+  div.block {
+    width: 100px;
+    height: 100px;
+    background-color: yellow;
+  }
+  div.column-span {
+    column-span: all;
+    height: 50px;
+    background-color: lightblue;
+  }
+  </style>
+
+  <article>
+    <div class="container">
+      <div class="block">block1</div>
+      <div class="column-span">column-span1</div>
+      <div class="block">block2</div>
+      <div class="column-span">column-span2</div>
+      <div class="block">block3</div>
+    </div>
+  </article>
+</html>
diff --git a/tests/wpt/web-platform-tests/css/css-overflow/float-with-relpos-and-transform.html b/tests/wpt/web-platform-tests/css/css-overflow/float-with-relpos-and-transform.html
new file mode 100644
index 00000000000..6024b726175
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-overflow/float-with-relpos-and-transform.html
@@ -0,0 +1,24 @@
+<!DOCTYPE html>
+<html>
+<link rel="help" href="https://drafts.csswg.org/css-overflow/#scrollable">
+<link rel="match" href="../reference/ref-filled-green-100px-square-only.html">
+<style>
+.container {
+  background: green;
+  width: 100px;
+  height: 100px;
+  overflow: auto;
+}
+.float {
+  float: left;
+  position: relative;
+  width: 50px;
+  height: 50px;
+  top: calc(50% - 100vh);
+  transform: translateY(-50%) translateY(100vh);
+}
+</style>
+<p>Test passes if there is a filled green square.</p>
+<div class="container">
+  <div class="float"></div>
+</div>
diff --git a/tests/wpt/web-platform-tests/css/css-paint-api/geometry-border-image-005-ref.html b/tests/wpt/web-platform-tests/css/css-paint-api/geometry-border-image-005-ref.html
new file mode 100644
index 00000000000..16d23041134
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-paint-api/geometry-border-image-005-ref.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<html>
+<style>
+html, body { margin: 0; padding: 0; }
+</style>
+<body>
+<canvas id ="canvas" width="308" height="308"></canvas>
+<script>
+var canvas = document.getElementById('canvas');
+var context = canvas.getContext("2d");
+context.fillStyle = "green";
+context.fillRect(0, 0, 290, 18);
+context.fillRect(0, 0, 18, 290);
+context.fillRect(0, 254, 290, 36);
+context.fillRect(254, 0, 36, 290);
+</script>
+</body>
+</html>
diff --git a/tests/wpt/web-platform-tests/css/css-paint-api/geometry-border-image-005.https.html b/tests/wpt/web-platform-tests/css/css-paint-api/geometry-border-image-005.https.html
new file mode 100644
index 00000000000..efdd7fdf1b9
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/css-paint-api/geometry-border-image-005.https.html
@@ -0,0 +1,37 @@
+<!DOCTYPE html>
+<html class="reftest-wait">
+<link rel="help" href="https://drafts.css-houdini.org/css-paint-api/">
+<link rel="match" href="geometry-border-image-005-ref.html">
+<style>
+html, body { margin: 0; padding: 0; }
+.container {
+  width: 200px;
+  height: 200px;
+  border: 36px solid orange;
+  border-image: paint(foo)               /* source */
+                1 /                      /* slice */
+                36px 36px 36px 36px /    /* width */
+                18px 18px 18px 18px      /* outset */
+                round;
+}
+</style>
+<script src="/common/reftest-wait.js"></script>
+<script src="/common/worklet-reftest.js"></script>
+<body>
+<div id="target" class="container"></div>
+
+<script id="code" type="text/worklet">
+registerPaint('foo', class {
+    paint(ctx, geom) {
+      // Both geom.width and height are 200 + 36 *3 = 308px;
+      ctx.fillStyle = 'green';
+      ctx.fillRect(0, 0, geom.width, geom.height);
+    }
+});
+</script>
+
+<script>
+    importWorkletAndTerminateTestAfterAsyncPaint(CSS.paintWorklet, document.getElementById('code').textContent);
+</script>
+</body>
+</html>
diff --git a/tests/wpt/web-platform-tests/css/css-position/position-absolute-replaced-minmax.html b/tests/wpt/web-platform-tests/css/css-position/position-absolute-replaced-minmax.html
index a5c0d516472..00780d650fa 100644
--- a/tests/wpt/web-platform-tests/css/css-position/position-absolute-replaced-minmax.html
+++ b/tests/wpt/web-platform-tests/css/css-position/position-absolute-replaced-minmax.html
@@ -261,7 +261,14 @@
 <!-- Just viewbox. Has aspect_ratio, but no intrinsic size
  inline_width is constrained by left/right, height computed proportionally -->
 <div class="container">
-  <img class="target" style="left:100px;right:100px" src="data:image/svg+xml,%3Csvg viewBox='0 0 100 10' xmlns='http://www.w3.org/2000/svg' %3E%3Crect width='100%' height='100%' style='fill:rgb(0,255,0);'/%3E%3C/svg%3E"
+  <img class="target" style="left:100px;right:100px;" src="data:image/svg+xml,%3Csvg viewBox='0 0 100 10' xmlns='http://www.w3.org/2000/svg' %3E%3Crect width='100%' height='100%' style='fill:rgb(0,255,0);'/%3E%3C/svg%3E"
+  data-expected-width="188" data-expected-height="47" data-offset-y="146" data-offset-x="109"
+  >
+</div>
+<!-- Same as previous test, but with max-width:fit-content. crbug.com/1010798
+  -->
+<div class="container">
+  <img class="target" style="left:100px;right:100px;max-width:fit-content" src="data:image/svg+xml,%3Csvg viewBox='0 0 100 10' xmlns='http://www.w3.org/2000/svg' %3E%3Crect width='100%' height='100%' style='fill:rgb(0,255,0);'/%3E%3C/svg%3E"
   data-expected-width="188" data-expected-height="47" data-offset-y="146" data-offset-x="109"
   >
 </div>
diff --git a/tests/wpt/web-platform-tests/docs/running-tests/webkitgtk_minibrowser.md b/tests/wpt/web-platform-tests/docs/running-tests/webkitgtk_minibrowser.md
index b12859bcca9..7aac81e5fce 100644
--- a/tests/wpt/web-platform-tests/docs/running-tests/webkitgtk_minibrowser.md
+++ b/tests/wpt/web-platform-tests/docs/running-tests/webkitgtk_minibrowser.md
@@ -18,15 +18,3 @@ to run it manually you can find it on any of this paths:
     inside:
     `/usr/lib/${TRIPLET}/webkit2gtk-4.0/MiniBrowser`
     where `TRIPLET=$(gcc -dumpmachine)`
-
-
-Known issues:
-
-* On a docker container WebKitWebDriver fails to listen on localhost,
-because the docker container doesn't provide an IPv6 localhost address.
-To workaround this issue, manually tell it to only listen on IPv4 localhost
-by passing this parameter to wpt run: `--webdriver-arg=--host=127.0.0.1`
-Example:
-```bash
-./wpt run --webdriver-arg=--host=127.0.0.1 webkitgtk_minibrowser TESTS
-```
diff --git a/tests/wpt/web-platform-tests/html/dom/idlharness.https.html b/tests/wpt/web-platform-tests/html/dom/idlharness.https.html
index 0d3f1160d28..33ad5c6f616 100644
--- a/tests/wpt/web-platform-tests/html/dom/idlharness.https.html
+++ b/tests/wpt/web-platform-tests/html/dom/idlharness.https.html
@@ -47,6 +47,7 @@ idl_test(
         documentWithHandlers[callback.name] = handler;
       }
     }
+    idlArray.add_untested_idls('typedef Window WindowProxy;');
 
     idlArray.add_objects({
       NodeList: ['document.getElementsByName("name")'],
diff --git a/tests/wpt/web-platform-tests/interfaces/feature-policy.idl b/tests/wpt/web-platform-tests/interfaces/feature-policy.idl
index 85601321a17..6f0d69fc378 100644
--- a/tests/wpt/web-platform-tests/interfaces/feature-policy.idl
+++ b/tests/wpt/web-platform-tests/interfaces/feature-policy.idl
@@ -3,7 +3,6 @@
 // (https://github.com/tidoust/reffy-reports)
 // Source: Feature Policy (https://w3c.github.io/webappsec-feature-policy/)
 
-[NoInterfaceObject]
 interface FeaturePolicy {
   boolean allowsFeature(DOMString feature, optional DOMString origin);
   sequence<DOMString> features();
diff --git a/tests/wpt/web-platform-tests/interfaces/webrtc-stats.idl b/tests/wpt/web-platform-tests/interfaces/webrtc-stats.idl
index e41d7357b1a..2b823047ff1 100644
--- a/tests/wpt/web-platform-tests/interfaces/webrtc-stats.idl
+++ b/tests/wpt/web-platform-tests/interfaces/webrtc-stats.idl
@@ -81,6 +81,7 @@ dictionary RTCInboundRtpStreamStats : RTCReceivedRtpStreamStats {
  boolean voiceActivityFlag;
  DOMHighResTimeStamp lastPacketReceivedTimestamp;
  double averageRtcpInterval;
+ unsigned long long headerBytesReceived;
  unsigned long long fecPacketsReceived;
  unsigned long long fecPacketsDiscarded;
  unsigned long long bytesReceived;
@@ -130,6 +131,7 @@ dictionary RTCOutboundRtpStreamStats : RTCSentRtpStreamStats {
              DOMString remoteId;
              DOMString rid;
              DOMHighResTimeStamp lastPacketSentTimestamp;
+             unsigned long long headerBytesSent;
              unsigned long packetsDiscardedOnSend;
              unsigned long long bytesDiscardedOnSend;
              unsigned long fecPacketsSent;
diff --git a/tests/wpt/web-platform-tests/mathml/presentation-markup/menclose/legacy-menclose-radical-notation-ref.html b/tests/wpt/web-platform-tests/mathml/presentation-markup/menclose/legacy-menclose-radical-notation-ref.html
index f0b5bdd9f04..c67ac03f5dc 100644
--- a/tests/wpt/web-platform-tests/mathml/presentation-markup/menclose/legacy-menclose-radical-notation-ref.html
+++ b/tests/wpt/web-platform-tests/mathml/presentation-markup/menclose/legacy-menclose-radical-notation-ref.html
@@ -12,7 +12,10 @@
   </head>
   <body>
     <math>
-      <menclose>
+      <menclose notation="">
+        <mn>123</mn>
+      </menclose>
+      <menclose notation="box">
         <mn>123</mn>
       </menclose>
     </math>
diff --git a/tests/wpt/web-platform-tests/mathml/presentation-markup/menclose/legacy-menclose-radical-notation.html b/tests/wpt/web-platform-tests/mathml/presentation-markup/menclose/legacy-menclose-radical-notation.html
index d7f0627059a..9b71389e74d 100644
--- a/tests/wpt/web-platform-tests/mathml/presentation-markup/menclose/legacy-menclose-radical-notation.html
+++ b/tests/wpt/web-platform-tests/mathml/presentation-markup/menclose/legacy-menclose-radical-notation.html
@@ -5,7 +5,7 @@
     <title>Legacy menclose radical notation</title>
     <link rel="help" href="https://www.w3.org/TR/MathML3/chapter3.html#presm.menclose">
     <link rel="help" href="https://mathml-refresh.github.io/mathml-core/#enclose-expression-inside-notation-menclose">
-    <meta name="assert" content="Verify that the legacy menclose radical notation is not supported.">
+    <meta name="assert" content="Verify that the legacy menclose radical notation is ignored.">
     <link rel="match" href="legacy-menclose-radical-notation-ref.html">
     <link rel="stylesheet" type="text/css" href="/fonts/ahem.css" />
     <style>
@@ -19,6 +19,9 @@
       <menclose notation="radical">
         <mn>123</mn>
       </menclose>
+      <menclose notation="box radical">
+        <mn>123</mn>
+      </menclose>
     </math>
 
    <script src="/mathml/support/feature-detection.js"></script>
diff --git a/tests/wpt/web-platform-tests/mathml/relations/html5-tree/tabindex-001.html b/tests/wpt/web-platform-tests/mathml/relations/html5-tree/tabindex-001.html
index aaf82f77caa..8f853688141 100644
--- a/tests/wpt/web-platform-tests/mathml/relations/html5-tree/tabindex-001.html
+++ b/tests/wpt/web-platform-tests/mathml/relations/html5-tree/tabindex-001.html
@@ -14,16 +14,20 @@
           const mrow = document.getElementById('mrow');
           assert_equals(mrow.tabIndex, -1, "no attribute");
           mrow.setAttribute("tabindex", "invalid");
+          assert_equals(mrow.getAttribute("tabindex"), "invalid");
           assert_equals(mrow.tabIndex, -1, "invalid");
           mrow.setAttribute("tabindex", "9999999999");
+          assert_equals(mrow.getAttribute("tabindex"), "9999999999");
           assert_equals(mrow.tabIndex, -1, "too large integer");
       }, "default and invalid values on mrow");
       test(() => {
           const mrowLink = document.getElementById('mrow-link');
           assert_equals(mrow.tabIndex, 0, "no attribute");
           mrow.setAttribute("tabindex", "invalid");
+          assert_equals(mrow.getAttribute("tabindex"), "invalid");
           assert_equals(mrow.tabIndex, 0, "invalid");
           mrow.setAttribute("tabindex", "9999999999");
+          assert_equals(mrow.getAttribute("tabindex"), "9999999999");
           assert_equals(mrow.tabIndex, 0, "too large integer");
       }, "default and invalid values on MathML link");
   });
diff --git a/tests/wpt/web-platform-tests/mediacapture-record/MediaRecorder-bitrate.https.html b/tests/wpt/web-platform-tests/mediacapture-record/MediaRecorder-bitrate.https.html
new file mode 100644
index 00000000000..472c0661cb7
--- /dev/null
+++ b/tests/wpt/web-platform-tests/mediacapture-record/MediaRecorder-bitrate.https.html
@@ -0,0 +1,226 @@
+<!doctype html>
+<html>
+<head>
+<title>MediaRecorder {audio|video}bitsPerSecond attributes</title>
+<link rel="help" href="https://w3c.github.io/mediacapture-record/MediaRecorder.html">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<script>
+
+/*
+ * The bitrate handling is difficult to test, given that the spec uses text such
+ * as: "values the User Agent deems reasonable" and "such that the sum of
+ * videoBitsPerSecond and audioBitsPerSecond is close to the value of recorder’s
+ * [[ConstrainedBitsPerSecond]] slot". For cases like that this test tries to
+ * use values that are reasonable for the tested track types. Should a UA vendor
+ * see a need to update this to fit their definition of reasonable, they should
+ * feel free to do so, doing their best to avoid regressing existing compliant
+ * implementations.
+ */
+
+async function getStream(t, constraints) {
+  const stream = await navigator.mediaDevices.getUserMedia(constraints);
+  const tracks = stream.getTracks();
+  t.add_cleanup(() => tracks.forEach(tr => tr.stop()));
+  return stream;
+}
+
+function getAudioStream(t) {
+  return getStream(t, {audio: true});
+}
+
+function getVideoStream(t) {
+  return getStream(t, {video: true});
+}
+
+function getAudioVideoStream(t) {
+  return getStream(t, {audio: true, video: true});
+}
+
+const AUDIO_BITRATE = 1e5;      // 100kbps
+const VIDEO_BITRATE = 1e6;      // 1Mbps
+const LOW_TOTAL_BITRATE = 5e5;  // 500kbps
+const HIGH_TOTAL_BITRATE = 2e6; // 2Mbps
+const BITRATE_EPSILON = 1e5;    // 100kbps
+
+promise_test(async t => {
+  const rec = new MediaRecorder(await getAudioVideoStream(t));
+  assert_not_equals(rec.audioBitsPerSecond, 0);
+  assert_not_equals(rec.videoBitsPerSecond, 0);
+}, "Passing no bitrate config results in defaults");
+
+promise_test(async t => {
+  const rec = new MediaRecorder(await getAudioVideoStream(t), {
+    bitsPerSecond: 0,
+  });
+  assert_not_equals(rec.audioBitsPerSecond, 0);
+  assert_not_equals(rec.videoBitsPerSecond, 0);
+  assert_approx_equals(rec.audioBitsPerSecond + rec.videoBitsPerSecond, 0,
+    BITRATE_EPSILON);
+}, "Passing bitsPerSecond:0 results in targets close to 0");
+
+promise_test(async t => {
+  const rec = new MediaRecorder(await getAudioVideoStream(t), {
+    audioBitsPerSecond: 0,
+  });
+  assert_equals(rec.audioBitsPerSecond, 0);
+  assert_not_equals(rec.videoBitsPerSecond, 0);
+}, "Passing only audioBitsPerSecond:0 results in 0 for audio, default for video");
+
+promise_test(async t => {
+  const rec = new MediaRecorder(await getAudioVideoStream(t), {
+    videoBitsPerSecond: 0,
+  });
+  assert_not_equals(rec.audioBitsPerSecond, 0);
+  assert_equals(rec.videoBitsPerSecond, 0);
+}, "Passing only videoBitsPerSecond:0 results in 0 for video, default for audio");
+
+promise_test(async t => {
+  const rec = new MediaRecorder(await getAudioVideoStream(t), {
+    bitsPerSecond: 0,
+    audioBitsPerSecond: AUDIO_BITRATE,
+    videoBitsPerSecond: VIDEO_BITRATE,
+  });
+  assert_not_equals(rec.audioBitsPerSecond, 0);
+  assert_not_equals(rec.videoBitsPerSecond, 0);
+  assert_approx_equals(rec.audioBitsPerSecond + rec.videoBitsPerSecond, 0,
+    BITRATE_EPSILON);
+}, "Passing bitsPerSecond:0 overrides audio/video-specific values");
+
+promise_test(async t => {
+  const rec = new MediaRecorder(await getAudioVideoStream(t), {
+    bitsPerSecond: HIGH_TOTAL_BITRATE,
+    audioBitsPerSecond: 0,
+    videoBitsPerSecond: 0,
+  });
+  assert_not_equals(rec.audioBitsPerSecond, 0);
+  assert_not_equals(rec.videoBitsPerSecond, 0);
+  assert_approx_equals(rec.audioBitsPerSecond + rec.videoBitsPerSecond,
+    HIGH_TOTAL_BITRATE, BITRATE_EPSILON);
+}, "Passing bitsPerSecond overrides audio/video zero values");
+
+promise_test(async t => {
+  const rec = new MediaRecorder(await getAudioVideoStream(t), {
+    bitsPerSecond: HIGH_TOTAL_BITRATE,
+  });
+  assert_not_equals(rec.audioBitsPerSecond, 0);
+  assert_not_equals(rec.videoBitsPerSecond, 0);
+  assert_approx_equals(rec.audioBitsPerSecond + rec.videoBitsPerSecond,
+    HIGH_TOTAL_BITRATE, BITRATE_EPSILON);
+}, "Passing bitsPerSecond sets audio/video bitrate values");
+
+promise_test(async t => {
+  const rec = new MediaRecorder(await getAudioVideoStream(t), {
+    audioBitsPerSecond: AUDIO_BITRATE,
+  });
+  assert_equals(rec.audioBitsPerSecond, AUDIO_BITRATE);
+  assert_not_equals(rec.videoBitsPerSecond, 0);
+}, "Passing only audioBitsPerSecond results in default for video");
+
+promise_test(async t => {
+  const rec = new MediaRecorder(await getAudioVideoStream(t), {
+    videoBitsPerSecond: VIDEO_BITRATE,
+  });
+  assert_not_equals(rec.audioBitsPerSecond, 0);
+  assert_equals(rec.videoBitsPerSecond, VIDEO_BITRATE);
+}, "Passing only videoBitsPerSecond results in default for audio");
+
+promise_test(async t => {
+  const rec = new MediaRecorder(await getAudioStream(t), {
+    videoBitsPerSecond: VIDEO_BITRATE,
+  });
+  assert_not_equals(rec.audioBitsPerSecond, 0);
+  assert_equals(rec.videoBitsPerSecond, VIDEO_BITRATE);
+}, "Passing videoBitsPerSecond for audio-only stream still results in something for video");
+
+promise_test(async t => {
+  const rec = new MediaRecorder(await getVideoStream(t), {
+    audioBitsPerSecond: AUDIO_BITRATE,
+  });
+  assert_equals(rec.audioBitsPerSecond, AUDIO_BITRATE);
+  assert_not_equals(rec.videoBitsPerSecond, 0);
+}, "Passing audioBitsPerSecond for video-only stream still results in something for audio");
+
+promise_test(async t => {
+  const rec = new MediaRecorder(await getAudioStream(t), {
+    bitsPerSecond: HIGH_TOTAL_BITRATE,
+  });
+  assert_not_equals(rec.audioBitsPerSecond, 0);
+  assert_not_equals(rec.videoBitsPerSecond, 0);
+}, "Passing bitsPerSecond for audio-only stream still results in something for video");
+
+promise_test(async t => {
+  const rec = new MediaRecorder(await getVideoStream(t), {
+    bitsPerSecond: HIGH_TOTAL_BITRATE,
+  });
+  assert_not_equals(rec.audioBitsPerSecond, 0);
+  assert_not_equals(rec.videoBitsPerSecond, 0);
+}, "Passing bitsPerSecond for video-only stream still results in something for audio");
+
+promise_test(async t => {
+  const rec = new MediaRecorder(await getAudioVideoStream(t));
+  t.add_cleanup(() => rec.stop());
+  const abps = rec.audioBitsPerSecond;
+  const vbps = rec.videoBitsPerSecond;
+  rec.start();
+  assert_equals(rec.audioBitsPerSecond, abps);
+  assert_equals(rec.videoBitsPerSecond, vbps);
+}, "Selected default track bitrates are not changed by start()");
+
+promise_test(async t => {
+  const rec = new MediaRecorder(await getAudioVideoStream(t), {
+    audioBitsPerSecond: AUDIO_BITRATE,
+    videoBitsPerSecond: VIDEO_BITRATE,
+  });
+  t.add_cleanup(() => rec.stop());
+  const abps = rec.audioBitsPerSecond;
+  const vbps = rec.videoBitsPerSecond;
+  rec.start();
+  assert_equals(rec.audioBitsPerSecond, abps);
+  assert_equals(rec.videoBitsPerSecond, vbps);
+}, "Passed-in track bitrates are not changed by start()");
+
+promise_test(async t => {
+  const rec = new MediaRecorder(await getAudioVideoStream(t), {
+    bitsPerSecond: HIGH_TOTAL_BITRATE,
+  });
+  t.add_cleanup(() => rec.stop());
+  const abps = rec.audioBitsPerSecond;
+  const vbps = rec.videoBitsPerSecond;
+  rec.start();
+  assert_equals(rec.audioBitsPerSecond, abps);
+  assert_equals(rec.videoBitsPerSecond, vbps);
+}, "Passing bitsPerSecond for audio/video stream does not change track bitrates in start()");
+
+promise_test(async t => {
+  const rec = new MediaRecorder(await getAudioStream(t), {
+    bitsPerSecond: LOW_TOTAL_BITRATE,
+  });
+  t.add_cleanup(() => rec.stop());
+  const abps = rec.audioBitsPerSecond;
+  const vbps = rec.videoBitsPerSecond;
+  rec.start();
+  assert_approx_equals(rec.audioBitsPerSecond, LOW_TOTAL_BITRATE,
+    BITRATE_EPSILON);
+  assert_equals(rec.videoBitsPerSecond, 0);
+  assert_not_equals(rec.audioBitsPerSecond, abps);
+  assert_not_equals(rec.videoBitsPerSecond, vbps);
+}, "Passing bitsPerSecond for audio stream sets video track bitrate to 0 in start()");
+
+promise_test(async t => {
+  const rec = new MediaRecorder(await getVideoStream(t), {
+    bitsPerSecond: HIGH_TOTAL_BITRATE,
+  });
+  t.add_cleanup(() => rec.stop());
+  const abps = rec.audioBitsPerSecond;
+  const vbps = rec.videoBitsPerSecond;
+  rec.start();
+  assert_equals(rec.audioBitsPerSecond, 0);
+  assert_approx_equals(rec.videoBitsPerSecond, HIGH_TOTAL_BITRATE,
+    BITRATE_EPSILON);
+  assert_not_equals(rec.audioBitsPerSecond, abps);
+  assert_not_equals(rec.videoBitsPerSecond, vbps);
+}, "Passing bitsPerSecond for video stream sets audio track bitrate to 0 in start()");
+</script>
+</html>
diff --git a/tests/wpt/web-platform-tests/mediacapture-record/MediaRecorder-creation.https.html b/tests/wpt/web-platform-tests/mediacapture-record/MediaRecorder-creation.https.html
index 419211c9dcf..b724ca14503 100644
--- a/tests/wpt/web-platform-tests/mediacapture-record/MediaRecorder-creation.https.html
+++ b/tests/wpt/web-platform-tests/mediacapture-record/MediaRecorder-creation.https.html
@@ -20,8 +20,8 @@
 
         var recorder = new MediaRecorder(stream);
         assert_equals(recorder.state, "inactive");
-        assert_equals(recorder.videoBitsPerSecond, 0);
-        assert_equals(recorder.audioBitsPerSecond, 0);
+        assert_not_equals(recorder.videoBitsPerSecond, 0);
+        assert_not_equals(recorder.audioBitsPerSecond, 0);
         test.done();
       });
 
diff --git a/tests/wpt/web-platform-tests/mediacapture-record/MediaRecorder-events-and-exceptions.html b/tests/wpt/web-platform-tests/mediacapture-record/MediaRecorder-events-and-exceptions.html
index 58b9c08ecab..cddc07e5079 100644
--- a/tests/wpt/web-platform-tests/mediacapture-record/MediaRecorder-events-and-exceptions.html
+++ b/tests/wpt/web-platform-tests/mediacapture-record/MediaRecorder-events-and-exceptions.html
@@ -36,23 +36,21 @@
     });
 
     recorderOnDataAvailable = test.step_func(event => {
-      // TODO(mcasas): ondataavailable might never be pinged with an empty Blob
-      // data on recorder.stop(), see http://crbug.com/54428
       assert_equals(recorder.state, "inactive");
-      assert_equals(event.data.size, 0, 'We should have gotten an empty Blob');
+      assert_not_equals(event.data.size, 0, 'We should get a Blob with data');
     });
 
     recorderOnStop = test.step_func(function() {
       assert_equals(recorder.state, "inactive");
-      assert_throws("InvalidStateError", function() { recorder.stop() },
-                    "recorder cannot be stop()ped in |inactive| state");
+      recorder.onstop = recorderOnUnexpectedEvent;
+      recorder.stop();
+      assert_equals(recorder.state, "inactive", "stop() is idempotent");
       assert_throws("InvalidStateError", function() { recorder.pause() },
                     "recorder cannot be pause()ed in |inactive| state");
       assert_throws("InvalidStateError", function() { recorder.resume() },
                     "recorder cannot be resume()d in |inactive| state");
       assert_throws("InvalidStateError", function() { recorder.requestData() },
                     "cannot requestData() if recorder is in |inactive| state");
-      recorder.onstop = recorderOnUnexpectedEvent;
       test.done();
     });
 
@@ -84,15 +82,15 @@
 
     assert_throws("NotSupportedError",
                   function() {
-                    recorder =
-                        new MediaRecorder(stream, {mimeType : "video/invalid"});
+                    recorder = new MediaRecorder(
+                      new MediaStream(), {mimeType : "video/invalid"});
                   },
                   "recorder should throw() with unsupported mimeType");
-    let recorder = new MediaRecorder(stream);
+    let recorder = new MediaRecorder(new MediaStream());
     assert_equals(recorder.state, "inactive");
 
-    assert_throws("InvalidStateError", function(){recorder.stop()},
-                  "recorder cannot be stop()ped in |inactive| state");
+    recorder.stop();
+    assert_equals(recorder.state, "inactive", "stop() is idempotent");
     assert_throws("InvalidStateError", function(){recorder.pause()},
                   "recorder cannot be pause()ed in |inactive| state");
     assert_throws("InvalidStateError", function(){recorder.resume()},
@@ -100,6 +98,14 @@
     assert_throws("InvalidStateError", function(){recorder.requestData()},
                   "cannot requestData() if recorder is in |inactive| state");
 
+    assert_throws("NotSupportedError",
+                  function() {
+                    recorder.start();
+                  },
+                  "recorder should throw() when starting with inactive stream");
+
+    recorder.stream.addTrack(stream.getTracks()[0]);
+
     drawSomethingOnCanvas();
 
     recorder.onstop = recorderOnUnexpectedEvent;
diff --git a/tests/wpt/web-platform-tests/mediacapture-record/MediaRecorder-mimetype.html b/tests/wpt/web-platform-tests/mediacapture-record/MediaRecorder-mimetype.html
new file mode 100644
index 00000000000..ddc56e9cb75
--- /dev/null
+++ b/tests/wpt/web-platform-tests/mediacapture-record/MediaRecorder-mimetype.html
@@ -0,0 +1,147 @@
+<!doctype html>
+<html>
+<head>
+  <title>MediaRecorder MIMEType</title>
+  <link rel="help" href="https://w3c.github.io/mediacapture-record/MediaRecorder.html#dom-mediarecorder-mimetype">
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+<canvas id="canvas" width="200" height="200">
+</canvas>
+<script>
+function createAudioStream(t) {
+  const ac = new AudioContext();
+  const {stream} = ac.createMediaStreamDestination();
+  const tracks = stream.getTracks();
+  t.add_cleanup(() => tracks.forEach(tr => tr.stop()));
+  return stream;
+}
+
+function createVideoStream(t) {
+  const canvas = document.getElementById("canvas");
+  canvas.getContext('2d');
+  const stream = canvas.captureStream();
+  const tracks = stream.getTracks();
+  t.add_cleanup(() => tracks.forEach(tr => tr.stop()));
+  return stream;
+}
+
+function createAudioVideoStream(t) {
+  return new MediaStream([
+      ...createAudioStream(t).getTracks(),
+      ...createVideoStream(t).getTracks(),
+    ]);
+}
+
+test(t => {
+  const recorder = new MediaRecorder(createAudioStream(t));
+  assert_equals(recorder.mimeType, "",
+    "MediaRecorder has no default MIMEtype");
+}, "MediaRecorder sets no default MIMEType in the constructor for audio");
+
+test(t => {
+  const recorder = new MediaRecorder(createVideoStream(t));
+  assert_equals(recorder.mimeType, "",
+    "MediaRecorder has no default MIMEtype");
+}, "MediaRecorder sets no default MIMEType in the constructor for video");
+
+test(t => {
+  const stream = createAudioVideoStream(t);
+  const recorder = new MediaRecorder(stream);
+  assert_equals(recorder.mimeType, "",
+    "MediaRecorder has no default MIMEtype");
+}, "MediaRecorder sets no default MIMEType in the constructor for audio/video");
+
+test(t => {
+  assert_throws("NotSupportedError",
+    () => new MediaRecorder(new MediaStream(), {mimeType: "audio/banana"}));
+}, "MediaRecorder invalid audio MIMEType throws");
+
+test(t => {
+  assert_false(MediaRecorder.isTypeSupported("audio/banana"));
+}, "MediaRecorder invalid audio MIMEType is unsupported");
+
+test(t => {
+  assert_throws("NotSupportedError",
+    () => new MediaRecorder(new MediaStream(), {mimeType: "video/pineapple"}));
+}, "MediaRecorder invalid video MIMEType throws");
+
+test(t => {
+  assert_false(MediaRecorder.isTypeSupported("video/pineapple"));
+}, "MediaRecorder invalid video MIMEType is unsupported");
+
+// New MIME types could be added to this list as needed.
+for (const mimeType of [
+  'audio/mp4',
+  'video/mp4',
+  'audio/ogg',
+  'audio/ogg; codecs="vorbis"',
+  'audio/ogg; codecs="opus"',
+  'audio/webm',
+  'audio/webm; codecs="vorbis"',
+  'audio/webm; codecs="opus"',
+  'video/webm',
+  'video/webm; codecs="vp8"',
+  'video/webm; codecs="vp8, vorbis"',
+  'video/webm; codecs="vp8, opus"',
+  'video/webm; codecs="vp9"',
+  'video/webm; codecs="vp9, vorbis"',
+  'video/webm; codecs="vp9, opus"',
+  'video/webm; codecs="av1"',
+  'video/webm; codecs="av1, opus"',
+]) {
+  if (MediaRecorder.isTypeSupported(mimeType)) {
+    test(t => {
+      const recorder = new MediaRecorder(new MediaStream(), {mimeType});
+      assert_equals(recorder.mimeType, mimeType, "Supported MIMEType is set");
+    }, `Supported MIMEType ${mimeType} is set immediately after constructing`);
+  } else {
+    test(t => {
+      assert_throws("NotSupportedError",
+        () => new MediaRecorder(new MediaStream(), {mimeType}));
+    }, `Unsupported MIMEType ${mimeType} throws`);
+  }
+}
+
+test(t => {
+  const recorder = new MediaRecorder(createAudioStream(t));
+  recorder.start();
+  assert_not_equals(recorder.mimeType, "",
+    "MediaRecorder has a MIMEtype after start() for audio");
+  assert_regexp_match(recorder.mimeType, /^audio\//,
+    "MIMEtype has an expected media type");
+  assert_regexp_match(recorder.mimeType, /^[a-z]+\/[a-z]+/,
+    "MIMEtype has a container subtype");
+  assert_regexp_match(recorder.mimeType, /^[a-z]+\/[a-z]+; codecs=[^,]+$/,
+    "MIMEtype has one codec");
+}, "MediaRecorder sets a MIMEType after start() for audio");
+
+test(t => {
+  const recorder = new MediaRecorder(createVideoStream(t));
+  recorder.start();
+  assert_not_equals(recorder.mimeType, "",
+    "MediaRecorder has a MIMEtype after start() for video");
+  assert_regexp_match(recorder.mimeType, /^video\//,
+    "MIMEtype has an expected media type");
+  assert_regexp_match(recorder.mimeType, /^[a-z]+\/[a-z]+/,
+    "MIMEtype has a container subtype");
+  assert_regexp_match(recorder.mimeType, /^[a-z]+\/[a-z]+; codecs=[^,]+$/,
+    "MIMEtype has one codec");
+}, "MediaRecorder sets a MIMEType after start() for video");
+
+test(t => {
+  const recorder = new MediaRecorder(createAudioVideoStream(t));
+  recorder.start();
+  assert_not_equals(recorder.mimeType, "",
+    "MediaRecorder has a MIMEtype after start() for audio/video");
+  assert_regexp_match(recorder.mimeType, /^video\//,
+    "MIMEtype has an expected media type");
+  assert_regexp_match(recorder.mimeType, /^[a-z]+\/[a-z]+/,
+    "MIMEtype has a container subtype");
+  assert_regexp_match(recorder.mimeType, /^[a-z]+\/[a-z]+; codecs=[^,]+,[^,]+$/,
+    "MIMEtype has two codecs");
+}, "MediaRecorder sets a MIMEType after start() for audio/video");
+</script>
+</body>
+</html>
diff --git a/tests/wpt/web-platform-tests/mediacapture-record/MediaRecorder-pause-resume.html b/tests/wpt/web-platform-tests/mediacapture-record/MediaRecorder-pause-resume.html
index 39a88836645..33dfd8560c0 100644
--- a/tests/wpt/web-platform-tests/mediacapture-record/MediaRecorder-pause-resume.html
+++ b/tests/wpt/web-platform-tests/mediacapture-record/MediaRecorder-pause-resume.html
@@ -11,8 +11,10 @@
 </canvas>
 <script>
     function createVideoStream() {
-        let canvas = document.getElementById("canvas");
-        canvas.getContext('2d');
+        const canvas = document.getElementById("canvas");
+        const ctx = canvas.getContext('2d');
+        ctx.fillStyle = 'green';
+        ctx.fillRect(0, 0, canvas.width, canvas.height);
         return canvas.captureStream();
     }
 
@@ -32,6 +34,7 @@
 
         recorder.start();
         assert_equals(recorder.state, "recording", "MediaRecorder has been started successfully");
+        await new Promise(r => recorder.onstart = r);
 
         recorder.pause();
         assert_equals(recorder.state, "paused", "MediaRecorder should be paused immediately following pause()");
diff --git a/tests/wpt/web-platform-tests/mediacapture-record/idlharness.window.js b/tests/wpt/web-platform-tests/mediacapture-record/idlharness.window.js
index 86f5a158822..2e304b0a0e6 100644
--- a/tests/wpt/web-platform-tests/mediacapture-record/idlharness.window.js
+++ b/tests/wpt/web-platform-tests/mediacapture-record/idlharness.window.js
@@ -7,7 +7,7 @@
 
 idl_test(
   ['mediastream-recording'],
-  ['mediacapture-streams', 'FileAPI', 'html', 'dom'],
+  ['mediacapture-streams', 'FileAPI', 'html', 'dom', 'WebIDL'],
   idl_array => {
     // Ignored errors will be surfaced in idlharness.js's test_object below.
     let recorder, blob, error;
@@ -31,7 +31,9 @@ idl_test(
     idl_array.add_objects({ BlobEvent: [blob] });
 
     try {
-      error = new MediaRecorderErrorEvent("type", {});
+      error = new MediaRecorderErrorEvent("type", {
+        error: new DOMException,
+      });
     } catch(e) {}
     idl_array.add_objects({ MediaRecorderErrorEvent: [error] });
   }
diff --git a/tests/wpt/web-platform-tests/resources/chromium/webxr-test.js b/tests/wpt/web-platform-tests/resources/chromium/webxr-test.js
index df91abf6d7f..94031657b4b 100644
--- a/tests/wpt/web-platform-tests/resources/chromium/webxr-test.js
+++ b/tests/wpt/web-platform-tests/resources/chromium/webxr-test.js
@@ -89,7 +89,7 @@ class MockVRService {
     this.runtimes_ = [];
 
     this.interceptor_ =
-        new MojoInterfaceInterceptor(device.mojom.VRService.name);
+        new MojoInterfaceInterceptor(device.mojom.VRService.name, "context", true);
     this.interceptor_.oninterfacerequest = e =>
         this.bindingSet_.addBinding(this, e.handle);
     this.interceptor_.start();
@@ -187,6 +187,15 @@ class MockVRService {
 // Implements XRFrameDataProvider and XRPresentationProvider. Maintains a mock
 // for XRPresentationProvider.
 class MockRuntime {
+  // Mapping from string feature names to the corresponding mojo types.
+  // This is exposed as a member for extensibility.
+  static featureToMojoMap = {
+    "viewer": device.mojom.XRSessionFeature.REF_SPACE_VIEWER,
+    "local": device.mojom.XRSessionFeature.REF_SPACE_LOCAL,
+    "local-floor": device.mojom.XRSessionFeature.REF_SPACE_LOCAL_FLOOR,
+    "bounded-floor": device.mojom.XRSessionFeature.REF_SPACE_BOUNDED_FLOOR,
+    "unbounded": device.mojom.XRSessionFeature.REF_SPACE_UNBOUNDED };
+
   constructor(fakeDeviceInit, service) {
     this.sessionClient_ = new device.mojom.XRSessionClientPtr();
     this.presentation_provider_ = new MockXRPresentationProvider();
@@ -456,19 +465,10 @@ class MockRuntime {
 
   setFeatures(supportedFeatures) {
     function convertFeatureToMojom(feature) {
-      switch (feature) {
-        case "viewer":
-          return device.mojom.XRSessionFeature.REF_SPACE_VIEWER;
-        case "local":
-          return device.mojom.XRSessionFeature.REF_SPACE_LOCAL;
-        case "local-floor":
-          return device.mojom.XRSessionFeature.REF_SPACE_LOCAL_FLOOR;
-        case "bounded-floor":
-          return device.mojom.XRSessionFeature.REF_SPACE_BOUNDED_FLOOR;
-        case "unbounded":
-          return device.mojom.XRSessionFeature.REF_SPACE_UNBOUNDED;
-        default:
-          return device.mojom.XRSessionFeature.INVALID;
+      if (feature in MockRuntime.featureToMojoMap) {
+        return MockRuntime.featureToMojoMap[feature];
+      } else {
+        return device.mojom.XRSessionFeature.INVALID;
       }
     }
 
diff --git a/tests/wpt/web-platform-tests/service-workers/service-worker/fetch-event-add-async.https.html b/tests/wpt/web-platform-tests/service-workers/service-worker/fetch-event-add-async.https.html
new file mode 100644
index 00000000000..ac13e4f4167
--- /dev/null
+++ b/tests/wpt/web-platform-tests/service-workers/service-worker/fetch-event-add-async.https.html
@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<title>Service Worker: Fetch event added asynchronously doesn't throw</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="resources/test-helpers.sub.js"></script>
+<script>
+'use strict';
+
+service_worker_test(
+  'resources/fetch-event-add-async-worker.js');
+</script>
diff --git a/tests/wpt/web-platform-tests/service-workers/service-worker/global-serviceworker.https.any.js b/tests/wpt/web-platform-tests/service-workers/service-worker/global-serviceworker.https.any.js
index 489b37f83e1..2335f635b2e 100644
--- a/tests/wpt/web-platform-tests/service-workers/service-worker/global-serviceworker.https.any.js
+++ b/tests/wpt/web-platform-tests/service-workers/service-worker/global-serviceworker.https.any.js
@@ -17,7 +17,7 @@ async_test((t) => {
   assert_true('serviceWorker' in self, 'self.serviceWorker exists');
   serviceWorker.postMessage({ messageTest: true });
 
-  // The rest of the rest runs once we receive the above message.
+  // The rest of the test runs once this receives the above message.
   addEventListener('message', t.step_func((event) => {
     // Ignore unrelated messages.
     if (!event.data.messageTest) return;
diff --git a/tests/wpt/web-platform-tests/service-workers/service-worker/resources/fetch-event-add-async-worker.js b/tests/wpt/web-platform-tests/service-workers/service-worker/resources/fetch-event-add-async-worker.js
new file mode 100644
index 00000000000..a5a44a57c99
--- /dev/null
+++ b/tests/wpt/web-platform-tests/service-workers/service-worker/resources/fetch-event-add-async-worker.js
@@ -0,0 +1,6 @@
+importScripts('/resources/testharness.js');
+
+promise_test(async () => {
+  await new Promise(handler => { step_timeout(handler, 0); });
+  self.addEventListener('fetch', () => {});
+}, 'fetch event added asynchronously does not throw');
diff --git a/tests/wpt/web-platform-tests/tools/ci/run_tc.py b/tests/wpt/web-platform-tests/tools/ci/run_tc.py
index b2826bf075e..3201ff3a9d3 100755
--- a/tests/wpt/web-platform-tests/tools/ci/run_tc.py
+++ b/tests/wpt/web-platform-tests/tools/ci/run_tc.py
@@ -145,6 +145,28 @@ def install_chrome(channel):
     run(["sudo", "apt-get", "-qqy", "update"])
     run(["sudo", "gdebi", "-qn", "/tmp/%s" % deb_archive])
 
+def install_webkitgtk_from_apt_repository(channel):
+    # Configure webkitgtk.org/debian repository for $channel and pin it with maximum priority
+    run(["sudo", "apt-key", "adv", "--fetch-keys", "https://webkitgtk.org/debian/apt.key"])
+    with open("/tmp/webkitgtk.list", "w") as f:
+        f.write("deb [arch=amd64] https://webkitgtk.org/debian buster-wpt-webkit-updates %s\n" % channel)
+    run(["sudo", "mv", "/tmp/webkitgtk.list", "/etc/apt/sources.list.d/"])
+    with open("/tmp/99webkitgtk", "w") as f:
+        f.write("Package: *\nPin: origin webkitgtk.org\nPin-Priority: 1999\n")
+    run(["sudo", "mv", "/tmp/99webkitgtk", "/etc/apt/preferences.d/"])
+    # Install webkit2gtk from the webkitgtk.org/debian repository for $channel
+    run(["sudo", "apt-get", "-qqy", "update"])
+    run(["sudo", "apt-get", "-qqy", "upgrade"])
+    run(["sudo", "apt-get", "-qqy", "-t", "buster-wpt-webkit-updates", "install", "webkit2gtk-driver"])
+
+
+def install_webkitgtk(channel):
+    if channel in ("experimental", "dev", "nightly"):
+        raise NotImplementedError("Still can't install from release channel: %s" % channel)
+    elif channel in ("beta", "stable"):
+        install_webkitgtk_from_apt_repository(channel)
+    else:
+        raise ValueError("Unrecognized release channel: %s" % channel)
 
 def start_xvfb():
     start(["sudo", "Xvfb", os.environ["DISPLAY"], "-screen", "0",
@@ -217,6 +239,9 @@ def setup_environment(args):
     if "chrome" in args.browser:
         assert args.channel is not None
         install_chrome(args.channel)
+    elif "webkitgtk_minibrowser" in args.browser:
+        assert args.channel is not None
+        install_webkitgtk(args.channel)
 
     if args.xvfb:
         start_xvfb()
diff --git a/tests/wpt/web-platform-tests/tools/docker/Dockerfile.webkitgtk b/tests/wpt/web-platform-tests/tools/docker/Dockerfile.webkitgtk
index 8d792b36a47..58080def60f 100644
--- a/tests/wpt/web-platform-tests/tools/docker/Dockerfile.webkitgtk
+++ b/tests/wpt/web-platform-tests/tools/docker/Dockerfile.webkitgtk
@@ -7,9 +7,13 @@ FROM debian:10
 ENV DEBIAN_FRONTEND=noninteractive \
     DEBCONF_NONINTERACTIVE_SEEN=true
 
-# Install general requirements not in the base image
+
+# Update and upgrade.
 RUN apt-get -qqy update \
-  && apt-get -qqy install \
+  && apt-get -qqy upgrade
+
+# Install general requirements not in the base image
+RUN apt-get -qqy install \
     bzip2 \
     ca-certificates \
     dbus-x11 \
@@ -29,19 +33,10 @@ RUN apt-get -qqy update \
     xvfb \
     git-core
 
-# Configure buster-wpt-webkit-updates repository
-RUN apt-key adv --fetch-keys https://webkitgtk.org/debian/apt.key
-RUN printf 'deb [arch=amd64] https://webkitgtk.org/debian buster-wpt-webkit-updates main' \
-    > /etc/apt/sources.list.d/webkitgtk.list
-RUN printf 'Package: *\nPin: origin webkitgtk.org\nPin-Priority: 1999' \
-    > /etc/apt/preferences.d/99webkitgtk
-
-# Update and upgrade
-RUN apt-get update \
-  && apt-get -y upgrade
 
-# Install webkit packages from https://webkitgtk.org/debian
-RUN apt-get install -y -t buster-wpt-webkit-updates webkit2gtk-driver
+# To speed up testers, cache in the image most of WebKitGTK dependencies
+# but don't install them (that will be done at test time)
+RUN apt-get install -qqy --download-only webkit2gtk-driver
 
 # Set the timezone
 ENV TZ "UTC"
diff --git a/tests/wpt/web-platform-tests/tools/docker/README.md b/tests/wpt/web-platform-tests/tools/docker/README.md
index c444e4a957f..6bcc47c7744 100644
--- a/tests/wpt/web-platform-tests/tools/docker/README.md
+++ b/tests/wpt/web-platform-tests/tools/docker/README.md
@@ -15,5 +15,3 @@ To update the image used for WebKitGTK:
 docker build -f Dockerfile.webkitgtk -t <tag> .
 docker push <tag>
 ```
-
-(This image is not yet used in .taskcluster.yml.)
diff --git a/tests/wpt/web-platform-tests/tools/wptrunner/wptrunner/browsers/base.py b/tests/wpt/web-platform-tests/tools/wptrunner/wptrunner/browsers/base.py
index 08b5880a1b7..d17229da468 100644
--- a/tests/wpt/web-platform-tests/tools/wptrunner/wptrunner/browsers/base.py
+++ b/tests/wpt/web-platform-tests/tools/wptrunner/wptrunner/browsers/base.py
@@ -36,6 +36,20 @@ def cmd_arg(name, value=None):
     return rv
 
 
+def maybe_add_args(required_args, current_args):
+    for required_arg in required_args:
+        # If the arg is in the form of "variable=value", only add it if
+        # no arg with another value for "variable" is already there.
+        if "=" in required_arg:
+            required_arg_prefix = "%s=" % required_arg.split("=")[0]
+            if not any(item.startswith(required_arg_prefix) for item in current_args):
+                current_args.append(required_arg)
+        else:
+            if required_arg not in current_args:
+                current_args.append(required_arg)
+    return current_args
+
+
 def get_free_port():
     """Get a random unbound port"""
     while True:
diff --git a/tests/wpt/web-platform-tests/tools/wptrunner/wptrunner/browsers/epiphany.py b/tests/wpt/web-platform-tests/tools/wptrunner/wptrunner/browsers/epiphany.py
index 599ec9f3110..37e2f21421a 100644
--- a/tests/wpt/web-platform-tests/tools/wptrunner/wptrunner/browsers/epiphany.py
+++ b/tests/wpt/web-platform-tests/tools/wptrunner/wptrunner/browsers/epiphany.py
@@ -1,4 +1,4 @@
-from .base import get_timeout_multiplier   # noqa: F401
+from .base import get_timeout_multiplier, maybe_add_args   # noqa: F401
 from .webkit import WebKitBrowser
 from ..executors import executor_kwargs as base_executor_kwargs
 from ..executors.executorwebdriver import (WebDriverTestharnessExecutor,  # noqa: F401
@@ -24,9 +24,12 @@ def check_args(**kwargs):
 
 
 def browser_kwargs(test_type, run_info_data, config, **kwargs):
+    # Workaround for https://gitlab.gnome.org/GNOME/libsoup/issues/172
+    webdriver_required_args = ["--host=127.0.0.1"]
+    webdriver_args = maybe_add_args(webdriver_required_args, kwargs.get("webdriver_args"))
     return {"binary": kwargs["binary"],
             "webdriver_binary": kwargs["webdriver_binary"],
-            "webdriver_args": kwargs.get("webdriver_args")}
+            "webdriver_args": webdriver_args}
 
 
 def capabilities(server_config, **kwargs):
diff --git a/tests/wpt/web-platform-tests/tools/wptrunner/wptrunner/browsers/firefox.py b/tests/wpt/web-platform-tests/tools/wptrunner/wptrunner/browsers/firefox.py
index 290fcff5ab2..1763ff44b4e 100644
--- a/tests/wpt/web-platform-tests/tools/wptrunner/wptrunner/browsers/firefox.py
+++ b/tests/wpt/web-platform-tests/tools/wptrunner/wptrunner/browsers/firefox.py
@@ -181,7 +181,7 @@ def run_info_browser_version(binary):
 
 
 def update_properties():
-    return (["os", "debug", "webrender", "e10s", "sw-e10s", "processor"],
+    return (["os", "debug", "webrender", "fisson", "e10s", "sw-e10s", "processor"],
             {"os": ["version"], "processor": ["bits"]})
 
 
diff --git a/tests/wpt/web-platform-tests/tools/wptrunner/wptrunner/browsers/webkitgtk_minibrowser.py b/tests/wpt/web-platform-tests/tools/wptrunner/wptrunner/browsers/webkitgtk_minibrowser.py
index 65f78125ad7..3c4947335bf 100644
--- a/tests/wpt/web-platform-tests/tools/wptrunner/wptrunner/browsers/webkitgtk_minibrowser.py
+++ b/tests/wpt/web-platform-tests/tools/wptrunner/wptrunner/browsers/webkitgtk_minibrowser.py
@@ -1,4 +1,4 @@
-from .base import get_timeout_multiplier   # noqa: F401
+from .base import get_timeout_multiplier, maybe_add_args   # noqa: F401
 from .webkit import WebKitBrowser
 from ..executors import executor_kwargs as base_executor_kwargs
 from ..executors.executorwebdriver import (WebDriverTestharnessExecutor,  # noqa: F401
@@ -24,16 +24,25 @@ def check_args(**kwargs):
 
 
 def browser_kwargs(test_type, run_info_data, config, **kwargs):
+    # Workaround for https://gitlab.gnome.org/GNOME/libsoup/issues/172
+    webdriver_required_args = ["--host=127.0.0.1"]
+    webdriver_args = maybe_add_args(webdriver_required_args, kwargs.get("webdriver_args"))
     return {"binary": kwargs["binary"],
             "webdriver_binary": kwargs["webdriver_binary"],
-            "webdriver_args": kwargs.get("webdriver_args")}
+            "webdriver_args": webdriver_args}
 
 
 def capabilities(server_config, **kwargs):
+    browser_required_args = ["--automation",
+                            "--javascript-can-open-windows-automatically=true",
+                            "--enable-xss-auditor=false",
+                            "--enable-media-capabilities=true",
+                            "--enable-encrypted-media=true",
+                            "--enable-media-stream=true",
+                            "--enable-mock-capture-devices=true",
+                            "--enable-webaudio=true"]
     args = kwargs.get("binary_args", [])
-    if "--automation" not in args:
-        args.append("--automation")
-
+    args = maybe_add_args(browser_required_args, args)
     return {
         "browserName": "MiniBrowser",
         "webkitgtk:browserOptions": {
diff --git a/tests/wpt/web-platform-tests/webaudio/the-audio-api/processing-model/cycle-witout-delay.html b/tests/wpt/web-platform-tests/webaudio/the-audio-api/processing-model/cycle-witout-delay.html
new file mode 100644
index 00000000000..ed26ad2ced2
--- /dev/null
+++ b/tests/wpt/web-platform-tests/webaudio/the-audio-api/processing-model/cycle-witout-delay.html
@@ -0,0 +1,35 @@
+<!DOCTYPE html>
+<html class="a">
+  <head>
+    <title>Cycles without DelayNode in audio node graph</title>
+    <script src="/resources/testharness.js"></script>
+    <script src="/resources/testharnessreport.js"></script>
+  </head>
+  <body>
+    <script>
+      const t = async_test(
+        "Test that cycles that don't contain a DelayNode are muted"
+      );
+      t.step(function() {
+          var off = new OfflineAudioContext(1, 512, 48000);
+          var osc = new OscillatorNode(off);
+          var fb = new GainNode(off);
+          // zero delay feedback loop
+          osc.connect(fb).connect(fb).connect(off.destination);
+          osc.start(0);
+          off.startRendering().then((b) => {
+              var samples = b.getChannelData(0);
+              var silent = true;
+              for (var i = 0; i < samples.length; i++) {
+                if (samples[i] != 0.0) {
+                  silent = false;
+                  break;
+                }
+              }
+              assert_true(silent);
+              t.done();
+          });
+      });
+    </script>
+  </body>
+</html>
diff --git a/tests/wpt/web-platform-tests/webaudio/the-audio-api/processing-model/delay-time-clamping.html b/tests/wpt/web-platform-tests/webaudio/the-audio-api/processing-model/delay-time-clamping.html
new file mode 100644
index 00000000000..3f8ed24429a
--- /dev/null
+++ b/tests/wpt/web-platform-tests/webaudio/the-audio-api/processing-model/delay-time-clamping.html
@@ -0,0 +1,38 @@
+<!DOCTYPE html>
+<html class="a">
+  <head>
+    <title>Delay time clamping in cycles</title>
+    <script src="/resources/testharness.js"></script>
+    <script src="/resources/testharnessreport.js"></script>
+  </head>
+  <body>
+    <script>
+      const t = async_test(
+        "Test that a DelayNode allows a feedback loop of a single rendering quantum"
+      );
+      t.step(function() {
+          var off = new OfflineAudioContext(1, 512, 48000);
+          var b = off.createBuffer(1, 1, 48000);
+          b.getChannelData(0)[0] = 1;
+          var impulse = new AudioBufferSourceNode(off, {buffer: b});
+          impulse.start(0);
+          // This delayTime of 64 samples MUST be clamped to 128 samples when
+          // in a cycle.
+          var delay = new DelayNode(off, {delayTime: 64/48000});
+          var fb = new GainNode(off);
+          impulse.connect(fb).connect(delay).connect(fb).connect(off.destination);
+          off.startRendering().then((b) => {
+              var samples = b.getChannelData(0);
+              for (var i = 0; i < samples.length; i++) {
+                if ((i % 128) != 0) {
+                  assert_equals(samples[i], 0.0, "Non-silent audio found in between delayed impulses");
+                } else {
+                  assert_equals(samples[i], 1.0, "Silent audio found instead of a delayed impulse");
+                }
+              }
+              t.done();
+          });
+      });
+    </script>
+  </body>
+</html>
diff --git a/tests/wpt/web-platform-tests/webaudio/the-audio-api/processing-model/feedback-delay-time.html b/tests/wpt/web-platform-tests/webaudio/the-audio-api/processing-model/feedback-delay-time.html
new file mode 100644
index 00000000000..50c8e455b90
--- /dev/null
+++ b/tests/wpt/web-platform-tests/webaudio/the-audio-api/processing-model/feedback-delay-time.html
@@ -0,0 +1,36 @@
+<!DOCTYPE html>
+<html class="a">
+  <head>
+    <title>Feedback cycle with delay in audio node graph</title>
+    <script src="/resources/testharness.js"></script>
+    <script src="/resources/testharnessreport.js"></script>
+  </head>
+  <body>
+    <script>
+      const t = async_test(
+        "Test that a DelayNode allows a feedback loop of a single rendering quantum"
+      );
+      t.step(function() {
+          var off = new OfflineAudioContext(1, 512, 48000);
+          var b = off.createBuffer(1, 1, 48000);
+          b.getChannelData(0)[0] = 1;
+          var impulse = new AudioBufferSourceNode(off, {buffer: b});
+          impulse.start(0);
+          var delay = new DelayNode(off, {delayTime: 128/48000});
+          var fb = new GainNode(off);
+          impulse.connect(fb).connect(delay).connect(fb).connect(off.destination);
+          off.startRendering().then((b) => {
+              var samples = b.getChannelData(0);
+              for (var i = 0; i < samples.length; i++) {
+                if ((i % 128) != 0) {
+                  assert_equals(samples[i], 0.0, "Non-silent audio found in between delayed impulses");
+                } else {
+                  assert_equals(samples[i], 1.0, "Silent audio found instead of a delayed impulse");
+                }
+              }
+              t.done();
+          });
+      });
+    </script>
+  </body>
+</html>