diff --git a/tests/wpt/metadata/MANIFEST.json b/tests/wpt/metadata/MANIFEST.json
index 3081e9d40de3..2cb3e5d81ef9 100644
--- a/tests/wpt/metadata/MANIFEST.json
+++ b/tests/wpt/metadata/MANIFEST.json
@@ -139153,9 +139153,9 @@
      {}
     ]
    ],
-   "css/css-pseudo/marker-content-007.html": [
+   "css/css-pseudo/marker-content-007.tentative.html": [
     [
-     "css/css-pseudo/marker-content-007.html",
+     "css/css-pseudo/marker-content-007.tentative.html",
      [
       [
        "/css/css-pseudo/marker-content-007-ref.html",
@@ -139165,9 +139165,9 @@
      {}
     ]
    ],
-   "css/css-pseudo/marker-content-008.html": [
+   "css/css-pseudo/marker-content-008.tentative.html": [
     [
-     "css/css-pseudo/marker-content-008.html",
+     "css/css-pseudo/marker-content-008.tentative.html",
      [
       [
        "/css/css-pseudo/marker-content-008-ref.html",
@@ -139177,9 +139177,9 @@
      {}
     ]
    ],
-   "css/css-pseudo/marker-content-009.html": [
+   "css/css-pseudo/marker-content-009.tentative.html": [
     [
-     "css/css-pseudo/marker-content-009.html",
+     "css/css-pseudo/marker-content-009.tentative.html",
      [
       [
        "/css/css-pseudo/marker-content-009-ref.html",
@@ -139201,9 +139201,9 @@
      {}
     ]
    ],
-   "css/css-pseudo/marker-content-011.html": [
+   "css/css-pseudo/marker-content-011.tentative.html": [
     [
-     "css/css-pseudo/marker-content-011.html",
+     "css/css-pseudo/marker-content-011.tentative.html",
      [
       [
        "/css/css-pseudo/marker-content-011-ref.html",
@@ -144453,18 +144453,6 @@
      {}
     ]
    ],
-   "css/css-sizing/ortho-writing-mode-001.html": [
-    [
-     "css/css-sizing/ortho-writing-mode-001.html",
-     [
-      [
-       "/css/reference/ref-filled-green-100px-square.xht",
-       "=="
-      ]
-     ],
-     {}
-    ]
-   ],
    "css/css-sizing/orthogonal-writing-mode-float-in-inline.html": [
     [
      "css/css-sizing/orthogonal-writing-mode-float-in-inline.html",
@@ -290576,6 +290564,12 @@
    "webauthn/helpers.js": [
     []
    ],
+   "webauthn/resources/common-inputs.js": [
+    []
+   ],
+   "webauthn/resources/utils.js": [
+    []
+   ],
    "webdriver/META.yml": [
     []
    ],
@@ -335867,6 +335861,12 @@
      {}
     ]
    ],
+   "css/cssom/border-shorthand-serialization.html": [
+    [
+     "css/cssom/border-shorthand-serialization.html",
+     {}
+    ]
+   ],
    "css/cssom/computed-style-001.html": [
     [
      "css/cssom/computed-style-001.html",
@@ -372669,6 +372669,12 @@
      {}
     ]
    ],
+   "loading/lazyload/disconnected-image-loading-lazy.tentative.html": [
+    [
+     "loading/lazyload/disconnected-image-loading-lazy.tentative.html",
+     {}
+    ]
+   ],
    "loading/lazyload/iframe-loading-eager.tentative.html": [
     [
      "loading/lazyload/iframe-loading-eager.tentative.html",
@@ -428143,6 +428149,14 @@
      {}
     ]
    ],
+   "webauthn/webauthn-testdriver-basic.https.html": [
+    [
+     "webauthn/webauthn-testdriver-basic.https.html",
+     {
+      "testdriver": true
+     }
+    ]
+   ],
    "webdriver/tests/interface.html": [
     [
      "webdriver/tests/interface.html",
@@ -588387,7 +588401,7 @@
    "8cec2799c2e0218e2e0c796ee4589b64d732cb39",
    "support"
   ],
-  "css/css-pseudo/marker-content-007.html": [
+  "css/css-pseudo/marker-content-007.tentative.html": [
    "fb452666e3c16094945ea5212e66cf04914f47f4",
    "reftest"
   ],
@@ -588395,7 +588409,7 @@
    "6d5052b378b7a5f626a51cb033fba8f7339192aa",
    "support"
   ],
-  "css/css-pseudo/marker-content-008.html": [
+  "css/css-pseudo/marker-content-008.tentative.html": [
    "88aee13dc8c9530967d73da7f09a609a40e483ac",
    "reftest"
   ],
@@ -588403,7 +588417,7 @@
    "a3db09f078148cdfe8105bc0d12186e15cf33d48",
    "support"
   ],
-  "css/css-pseudo/marker-content-009.html": [
+  "css/css-pseudo/marker-content-009.tentative.html": [
    "b3627cca7554076f85d59869eec7bc80e39b82be",
    "reftest"
   ],
@@ -588419,7 +588433,7 @@
    "62a64a1e5e16ac7d90ada265317235cfb6dbe64f",
    "support"
   ],
-  "css/css-pseudo/marker-content-011.html": [
+  "css/css-pseudo/marker-content-011.tentative.html": [
    "0cc20b0cdcd242021bc37b9e2d3500ed21c5b35f",
    "reftest"
   ],
@@ -593299,10 +593313,6 @@
    "d2617f8aa2d1c966e394abb1d1617c012ea4648e",
    "testharness"
   ],
-  "css/css-sizing/ortho-writing-mode-001.html": [
-   "9342802645faa7b57a12ce4b8ef17d755fcaface",
-   "reftest"
-  ],
   "css/css-sizing/orthogonal-writing-mode-float-in-inline.html": [
    "fa95069dbf0083b0dc7095d2bb3acf20a6ccf898",
    "reftest"
@@ -621315,6 +621325,10 @@
    "04a8a2289aa67e05a359ece1d09d961539d82571",
    "testharness"
   ],
+  "css/cssom/border-shorthand-serialization.html": [
+   "9b5821563c49c8874f7bbd8dc4ffb2f9813a789e",
+   "testharness"
+  ],
   "css/cssom/computed-style-001.html": [
    "d637b066b03a71283ad89315a5c346a1715900f1",
    "testharness"
@@ -667903,6 +667917,10 @@
    "0a7b408b649fe04604b6f08188a2399eefbbd0a4",
    "support"
   ],
+  "loading/lazyload/disconnected-image-loading-lazy.tentative.html": [
+   "c3b72b26239ea18c0575b65d0d6aa3aaef08792d",
+   "testharness"
+  ],
   "loading/lazyload/iframe-loading-eager.tentative.html": [
    "26209332ff5a0c4af64e0ae4893f1c396a111ce1",
    "testharness"
@@ -701824,7 +701842,7 @@
    "support"
   ],
   "svg/META.yml": [
-   "ee0fff087c4f9a5723f53cc002e228a713e730da",
+   "a928f0c399126a5e463e1497c4a454dabe6f24fe",
    "support"
   ],
   "svg/README.md": [
@@ -718336,7 +718354,7 @@
    "testharness"
   ],
   "web-animations/interfaces/Animatable/animate.html": [
-   "2d09cdf4545e8073786215169fd3f26c28a7e119",
+   "95d7db7bb3ba36fc9a0914ebe0d2c8e910e29cf1",
    "testharness"
   ],
   "web-animations/interfaces/Animatable/getAnimations.html": [
@@ -718468,7 +718486,7 @@
    "testharness"
   ],
   "web-animations/interfaces/KeyframeEffect/target.html": [
-   "10f42eea4e5b406c822802c1078fcc1295cb8a39",
+   "a9827d64d3d076185daee4787589832cc74f0ec0",
    "testharness"
   ],
   "web-animations/resources/easing-tests.js": [
@@ -719428,11 +719446,11 @@
    "testharness"
   ],
   "webaudio/the-audio-api/the-audioworklet-interface/audioworkletglobalscope-sample-rate.https.html": [
-   "d87e35b571d75c0ff595ab023f4a54a420111523",
+   "84458d0aaa77788b6de7ccd09b64f18a6bf9ede4",
    "testharness"
   ],
   "webaudio/the-audio-api/the-audioworklet-interface/audioworkletglobalscope-timing-info.https.html": [
-   "79d402c51862f019413f4ed789bbe8ce4b27e175",
+   "5f4bee7c5312c89207a25801cd0c2d6055ec00b5",
    "testharness"
   ],
   "webaudio/the-audio-api/the-audioworklet-interface/audioworkletnode-automatic-pull.https.html": [
@@ -719456,11 +719474,11 @@
    "testharness"
   ],
   "webaudio/the-audio-api/the-audioworklet-interface/audioworkletnode-onerror.https.html": [
-   "0a9966add85c6cdd35ce54eb05aae0986c5d9b8e",
+   "0914edbb3b0ababb646784be605177c8e4a79a09",
    "testharness"
   ],
   "webaudio/the-audio-api/the-audioworklet-interface/audioworkletnode-output-channel-count.https.html": [
-   "9d65d872b987943491cace95b8cdf729158fbd0d",
+   "a8a7f5ed1de78b90432641d617e60a1b58dd893f",
    "testharness"
   ],
   "webaudio/the-audio-api/the-audioworklet-interface/audioworkletprocessor-options.https.html": [
@@ -719812,7 +719830,7 @@
    "support"
   ],
   "webaudio/the-audio-api/the-mediaelementaudiosourcenode-interface/cors-check.https.html": [
-   "a2fa8040b2c6100f7ec22f0f133525808403ce01",
+   "38bd94a037c3b15e59fe6e99acbf013636de9003",
    "testharness"
   ],
   "webaudio/the-audio-api/the-mediaelementaudiosourcenode-interface/mediaElementAudioSourceToScriptProcessorTest.html": [
@@ -719820,7 +719838,7 @@
    "testharness"
   ],
   "webaudio/the-audio-api/the-mediaelementaudiosourcenode-interface/no-cors.https.html": [
-   "38324a9f67a67f50f134fb78af43117e2ec9b8c8",
+   "de2f0b7dd3b680cbb38d1b0546c6656b1e03e1b2",
    "testharness"
   ],
   "webaudio/the-audio-api/the-mediastreamaudiodestinationnode-interface/.gitkeep": [
@@ -720067,6 +720085,14 @@
    "ff0efcb656a740e9fdee2a3cc8dbfddda9b2a563",
    "testharness"
   ],
+  "webauthn/resources/common-inputs.js": [
+   "8370f7f079a014ea58dd3ce606b7fa48dcc88a3e",
+   "support"
+  ],
+  "webauthn/resources/utils.js": [
+   "f361a94d2e4f63b18bf1f7f2971db6322a30000f",
+   "support"
+  ],
   "webauthn/securecontext.http.html": [
    "52786950f383eb0454edcf9fad9b637dde956ca8",
    "testharness"
@@ -720075,6 +720101,10 @@
    "6c9aabd11ea3a51688962890dde29d5c41ec6c6f",
    "testharness"
   ],
+  "webauthn/webauthn-testdriver-basic.https.html": [
+   "7790f5d0d3fd7567df24a3aeebc4d7541c118e1a",
+   "testharness"
+  ],
   "webdriver/META.yml": [
    "a397b497c32234d3889c738f51b96a3ba3b2a96f",
    "support"
diff --git a/tests/wpt/metadata/css/cssom/border-shorthand-serialization.html.ini b/tests/wpt/metadata/css/cssom/border-shorthand-serialization.html.ini
new file mode 100644
index 000000000000..5e4163cc85dd
--- /dev/null
+++ b/tests/wpt/metadata/css/cssom/border-shorthand-serialization.html.ini
@@ -0,0 +1,4 @@
+[border-shorthand-serialization.html]
+  [Declaration with border longhands and border-image is not serialized to a border shorthand declaration.]
+    expected: FAIL
+
diff --git a/tests/wpt/metadata/fetch/content-type/response.window.js.ini b/tests/wpt/metadata/fetch/content-type/response.window.js.ini
index 0f615a03436f..0d3a1c211047 100644
--- a/tests/wpt/metadata/fetch/content-type/response.window.js.ini
+++ b/tests/wpt/metadata/fetch/content-type/response.window.js.ini
@@ -309,18 +309,21 @@
   [<iframe>: separate response Content-Type: */* text/html]
     expected: FAIL
 
-  [<iframe>: combined response Content-Type: text/html;x=" text/plain]
+  [<iframe>: separate response Content-Type: text/html;" text/plain]
     expected: FAIL
 
-  [<iframe>: separate response Content-Type: text/html;" text/plain]
+  [<iframe>: combined response Content-Type: text/html;" \\" text/plain]
     expected: FAIL
 
-  [<iframe>: combined response Content-Type: text/html */*]
+  [<iframe>: combined response Content-Type: text/html;charset=gbk text/plain text/html]
     expected: FAIL
 
-  [<iframe>: combined response Content-Type: text/html */*;charset=gbk]
+  [<iframe>: separate response Content-Type: text/html */*;charset=gbk]
     expected: FAIL
 
-  [<iframe>: combined response Content-Type: text/html;" \\" text/plain]
+  [<iframe>: separate response Content-Type: text/html */*]
+    expected: FAIL
+
+  [<iframe>: separate 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 d2df9b78483b..5c0015928591 100644
--- a/tests/wpt/metadata/fetch/content-type/script.window.js.ini
+++ b/tests/wpt/metadata/fetch/content-type/script.window.js.ini
@@ -56,3 +56,6 @@
   [separate text/javascript x/x]
     expected: FAIL
 
+  [separate text/javascript;charset=windows-1252 error 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 536384f36e1c..d4ba399b7623 100644
--- a/tests/wpt/metadata/fetch/nosniff/parsing-nosniff.window.js.ini
+++ b/tests/wpt/metadata/fetch/nosniff/parsing-nosniff.window.js.ini
@@ -11,6 +11,6 @@
   [X-Content-Type-Options%3A%20nosniff%0C]
     expected: FAIL
 
-  [X-Content-Type-Options%3A%20%2Cnosniff]
+  [X-Content-Type-Options%3A%20'NosniFF']
     expected: FAIL
 
diff --git a/tests/wpt/metadata/fetch/security/embedded-credentials.tentative.sub.html.ini b/tests/wpt/metadata/fetch/security/embedded-credentials.tentative.sub.html.ini
index 6bd06899fdd3..a3a600c5846a 100644
--- a/tests/wpt/metadata/fetch/security/embedded-credentials.tentative.sub.html.ini
+++ b/tests/wpt/metadata/fetch/security/embedded-credentials.tentative.sub.html.ini
@@ -1,6 +1,5 @@
 [embedded-credentials.tentative.sub.html]
   type: testharness
-  expected: TIMEOUT
   [Embedded credentials are treated as network errors.]
     expected: FAIL
 
@@ -11,11 +10,5 @@
     expected: FAIL
 
   [Embedded credentials matching the top-level are treated as network errors for cross-origin URLs.]
-    expected: TIMEOUT
-
-  [Embedded credentials matching the top-level are not treated as network errors for same-origin URLs.]
-    expected: TIMEOUT
-
-  [Embedded credentials matching the top-level are not treated as network errors for relative URLs.]
-    expected: TIMEOUT
+    expected: FAIL
 
diff --git a/tests/wpt/metadata/html/browsers/history/the-history-interface/traverse_the_history_2.html.ini b/tests/wpt/metadata/html/browsers/history/the-history-interface/traverse_the_history_2.html.ini
deleted file mode 100644
index 75d75b4cda2e..000000000000
--- a/tests/wpt/metadata/html/browsers/history/the-history-interface/traverse_the_history_2.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[traverse_the_history_2.html]
-  [Multiple history traversals, last would be aborted]
-    expected: FAIL
-
diff --git a/tests/wpt/metadata/html/browsers/history/the-history-interface/traverse_the_history_5.html.ini b/tests/wpt/metadata/html/browsers/history/the-history-interface/traverse_the_history_5.html.ini
deleted file mode 100644
index dc2e45516deb..000000000000
--- a/tests/wpt/metadata/html/browsers/history/the-history-interface/traverse_the_history_5.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[traverse_the_history_5.html]
-  [Multiple history traversals, last would be aborted]
-    expected: FAIL
-
diff --git a/tests/wpt/metadata/html/interaction/focus/the-autofocus-attribute/supported-elements.html.ini b/tests/wpt/metadata/html/interaction/focus/the-autofocus-attribute/supported-elements.html.ini
index 8b743f36e1dc..6b68e9094e40 100644
--- a/tests/wpt/metadata/html/interaction/focus/the-autofocus-attribute/supported-elements.html.ini
+++ b/tests/wpt/metadata/html/interaction/focus/the-autofocus-attribute/supported-elements.html.ini
@@ -1,20 +1,16 @@
 [supported-elements.html]
-  expected: TIMEOUT
   [Contenteditable element should support autofocus]
     expected: FAIL
 
   [Element with tabindex should support autofocus]
-    expected: TIMEOUT
+    expected: FAIL
 
   [Host element with delegatesFocus including no focusable descendants should be skipped]
-    expected: NOTRUN
+    expected: FAIL
 
   [Area element should support autofocus]
-    expected: NOTRUN
+    expected: FAIL
 
   [Host element with delegatesFocus should support autofocus]
-    expected: NOTRUN
-
-  [Non-HTMLElement should not support autofocus]
-    expected: NOTRUN
+    expected: FAIL
 
diff --git a/tests/wpt/metadata/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_escaping-3.html.ini b/tests/wpt/metadata/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_escaping-3.html.ini
index 5f60c78e73cd..f6a7aca3306c 100644
--- a/tests/wpt/metadata/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_escaping-3.html.ini
+++ b/tests/wpt/metadata/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_escaping-3.html.ini
@@ -1,6 +1,5 @@
 [iframe_sandbox_popups_escaping-3.html]
   type: testharness
-  expected: TIMEOUT
   [Check that popups from a sandboxed iframe escape the sandbox if\n       allow-popups-to-escape-sandbox is used]
-    expected: TIMEOUT
+    expected: FAIL
 
diff --git a/tests/wpt/metadata/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_nonescaping-3.html.ini b/tests/wpt/metadata/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_nonescaping-3.html.ini
index dc856a3d5a31..e440b1e38c61 100644
--- a/tests/wpt/metadata/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_nonescaping-3.html.ini
+++ b/tests/wpt/metadata/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_nonescaping-3.html.ini
@@ -1,5 +1,6 @@
 [iframe_sandbox_popups_nonescaping-3.html]
   type: testharness
+  expected: TIMEOUT
   [Check that popups from a sandboxed iframe do not escape the sandbox]
-    expected: FAIL
+    expected: NOTRUN
 
diff --git a/tests/wpt/metadata/html/semantics/forms/form-submission-0/form-double-submit-2.html.ini b/tests/wpt/metadata/html/semantics/forms/form-submission-0/form-double-submit-2.html.ini
index f6eecd82b494..61799e4c9356 100644
--- a/tests/wpt/metadata/html/semantics/forms/form-submission-0/form-double-submit-2.html.ini
+++ b/tests/wpt/metadata/html/semantics/forms/form-submission-0/form-double-submit-2.html.ini
@@ -1,5 +1,5 @@
 [form-double-submit-2.html]
   expected: ERROR
   [preventDefault should allow onclick submit() to succeed]
-    expected: TIMEOUT
+    expected: FAIL
 
diff --git a/tests/wpt/metadata/html/semantics/forms/form-submission-0/form-double-submit.html.ini b/tests/wpt/metadata/html/semantics/forms/form-submission-0/form-double-submit.html.ini
index dce74c6dd71d..47a7bbb7975f 100644
--- a/tests/wpt/metadata/html/semantics/forms/form-submission-0/form-double-submit.html.ini
+++ b/tests/wpt/metadata/html/semantics/forms/form-submission-0/form-double-submit.html.ini
@@ -1,5 +1,5 @@
 [form-double-submit.html]
   expected: ERROR
   [default submit action should supersede onclick submit()]
-    expected: FAIL
+    expected: TIMEOUT
 
diff --git a/tests/wpt/metadata/html/semantics/scripting-1/the-script-element/script-onerror-insertion-point-2.html.ini b/tests/wpt/metadata/html/semantics/scripting-1/the-script-element/script-onerror-insertion-point-2.html.ini
deleted file mode 100644
index 178680e5d146..000000000000
--- a/tests/wpt/metadata/html/semantics/scripting-1/the-script-element/script-onerror-insertion-point-2.html.ini
+++ /dev/null
@@ -1,2 +0,0 @@
-[script-onerror-insertion-point-2.html]
-  expected: TIMEOUT
diff --git a/tests/wpt/metadata/workers/constructors/Worker/Worker-constructor.html.ini b/tests/wpt/metadata/workers/constructors/Worker/Worker-constructor.html.ini
deleted file mode 100644
index 80f9a4f15b8a..000000000000
--- a/tests/wpt/metadata/workers/constructors/Worker/Worker-constructor.html.ini
+++ /dev/null
@@ -1,2 +0,0 @@
-[Worker-constructor.html]
-  expected: ERROR
diff --git a/tests/wpt/web-platform-tests/css/css-pseudo/marker-content-007.html b/tests/wpt/web-platform-tests/css/css-pseudo/marker-content-007.tentative.html
similarity index 100%
rename from tests/wpt/web-platform-tests/css/css-pseudo/marker-content-007.html
rename to tests/wpt/web-platform-tests/css/css-pseudo/marker-content-007.tentative.html
diff --git a/tests/wpt/web-platform-tests/css/css-pseudo/marker-content-008.html b/tests/wpt/web-platform-tests/css/css-pseudo/marker-content-008.tentative.html
similarity index 100%
rename from tests/wpt/web-platform-tests/css/css-pseudo/marker-content-008.html
rename to tests/wpt/web-platform-tests/css/css-pseudo/marker-content-008.tentative.html
diff --git a/tests/wpt/web-platform-tests/css/css-pseudo/marker-content-009.html b/tests/wpt/web-platform-tests/css/css-pseudo/marker-content-009.tentative.html
similarity index 100%
rename from tests/wpt/web-platform-tests/css/css-pseudo/marker-content-009.html
rename to tests/wpt/web-platform-tests/css/css-pseudo/marker-content-009.tentative.html
diff --git a/tests/wpt/web-platform-tests/css/css-pseudo/marker-content-011.html b/tests/wpt/web-platform-tests/css/css-pseudo/marker-content-011.tentative.html
similarity index 100%
rename from tests/wpt/web-platform-tests/css/css-pseudo/marker-content-011.html
rename to tests/wpt/web-platform-tests/css/css-pseudo/marker-content-011.tentative.html
diff --git a/tests/wpt/web-platform-tests/css/css-sizing/ortho-writing-mode-001.html b/tests/wpt/web-platform-tests/css/css-sizing/ortho-writing-mode-001.html
deleted file mode 100644
index 9342802645fa..000000000000
--- a/tests/wpt/web-platform-tests/css/css-sizing/ortho-writing-mode-001.html
+++ /dev/null
@@ -1,16 +0,0 @@
-<!DOCTYPE html>
-<link rel="author" title="David Grogan" href="mailto:dgrogan@chromium.org">
-<link rel="author" title="Morten Stenshorne" href="mailto:mstensho@chromium.org">
-<link rel="help" href="https://drafts.csswg.org/css-sizing-3/#intrinsic-sizes" title="first paragraph">
-<link rel="help" href="https://www.w3.org/TR/css-writing-modes-4/#orthogonal-auto">
-<link rel="match" href="../reference/ref-filled-green-100px-square.xht">
-<meta name="flags" content="" />
-<meta name="assert" content="The intrinsic size of an orthogonal child is its shrink to fit size after layout" />
-
-<p>Test passes if there is a filled green square and <strong>no red</strong>.</p>
-
-<div style="width:min-content; background:red;">
-  <div style="writing-mode:vertical-rl; background:green;">
-    <div style="margin-right:50%; width:50px; height:100px;"></div>
-  </div>
-</div>
diff --git a/tests/wpt/web-platform-tests/css/cssom/border-shorthand-serialization.html b/tests/wpt/web-platform-tests/css/cssom/border-shorthand-serialization.html
new file mode 100644
index 000000000000..9b5821563c49
--- /dev/null
+++ b/tests/wpt/web-platform-tests/css/cssom/border-shorthand-serialization.html
@@ -0,0 +1,42 @@
+<!doctype html>
+<html>
+<link rel="author" title="Erik Nordin" href="mailto:enordin@mozilla.com">
+<link rel="help" href="https://drafts.csswg.org/css-backgrounds-3/#propdef-border">
+<link rel="help" href="https://drafts.csswg.org/cssom-1/#serialize-a-css-declaration-block">
+<link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1594241">
+<meta charset="utf-8">
+<title>serialization of border shorthand</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<style id="target">
+    .a {
+        border-width: 1px;
+        border-style: solid;
+        border-color: black;
+    }
+    .b {
+        border-width: 1px;
+        border-style: solid;
+        border-color: black;
+        border-image: linear-gradient(white,black);
+    }
+    .c {
+        border: 1px solid black;
+    }
+</style>
+<script>
+    test(function() {
+        let rule = document.getElementById('target').sheet.cssRules[0];
+        assert_equals(rule.style.border, "", "border shorthand isn't serialized if border-image longhands are not initial");
+    }, "Declaration with border longhands is not serialized to a border shorthand declaration.");
+    test(function() {
+        let rule = document.getElementById('target').sheet.cssRules[1];
+        assert_equals(rule.style.border, "", "border shorthand isn't serialized if border-image longhands are not initial");
+    }, "Declaration with border longhands and border-image is not serialized to a border shorthand declaration.");
+    test(function() {
+        let rule = document.getElementById('target').sheet.cssRules[2];
+        assert_not_equals(rule.style.border, "", "border shorthand ");
+        assert_equals(rule.cssText, ".c { border: 1px solid black; }");
+    }, "Border shorthand is serialized correctly if all border-image-* are set to their initial specified values.");
+</script>
+</html>
diff --git a/tests/wpt/web-platform-tests/loading/lazyload/disconnected-image-loading-lazy.tentative.html b/tests/wpt/web-platform-tests/loading/lazyload/disconnected-image-loading-lazy.tentative.html
new file mode 100644
index 000000000000..c3b72b26239e
--- /dev/null
+++ b/tests/wpt/web-platform-tests/loading/lazyload/disconnected-image-loading-lazy.tentative.html
@@ -0,0 +1,30 @@
+<!DOCTYPE html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<body>
+<script>
+async_test(function(t) {
+  x = new Image();
+  x.loading = "auto";
+  x.src = "resources/image.png?auto";
+  x.onload = e => {
+    t.step(function() {
+      t.step_func_done();
+    });
+  };
+  t.step_timeout(function() { t.done(); }, 2000);
+}, "loading=auto for disconnected image");
+
+async_test(function(t) {
+  x = new Image();
+  x.loading = "lazy";
+  x.src = "resources/image.png?lazy";
+  x.onload = e => {
+    t.step(function() {
+      t.unreached_func("Disconnected image with loading=lazy should be loaded lazily.");
+    });
+  };
+  t.step_timeout(function() { t.done(); }, 2000);
+}, "loading=lazy for disconnected image");
+</script>
+</body>
diff --git a/tests/wpt/web-platform-tests/svg/META.yml b/tests/wpt/web-platform-tests/svg/META.yml
index ee0fff087c4f..a928f0c39912 100644
--- a/tests/wpt/web-platform-tests/svg/META.yml
+++ b/tests/wpt/web-platform-tests/svg/META.yml
@@ -7,3 +7,4 @@ suggested_reviewers:
   - svgeesus
   - dirkschulze
   - fsoder
+  - shallawa
diff --git a/tests/wpt/web-platform-tests/web-animations/interfaces/Animatable/animate.html b/tests/wpt/web-platform-tests/web-animations/interfaces/Animatable/animate.html
index 2d09cdf4545e..95d7db7bb3ba 100644
--- a/tests/wpt/web-platform-tests/web-animations/interfaces/Animatable/animate.html
+++ b/tests/wpt/web-platform-tests/web-animations/interfaces/Animatable/animate.html
@@ -241,18 +241,28 @@
 }, 'Element.animate() does NOT trigger a style change event');
 
 // Tests on pseudo-elements
+// Some tests occur twice (on pseudo-elements with and without content)
+// in order to test both code paths for tree-abiding pseudo-elements in blink.
 
 test(t => {
   const div = createDiv(t);
   div.classList.add('pseudo');
+  getComputedStyle(div,"::before").content; // Sync style
   const anim = div.animate(null, {pseudoElement: '::before'});
   assert_class_string(anim, 'Animation', 'The returned object is an Animation');
 }, 'animate() with pseudoElement parameter creates an Animation object');
 
+test(t => {
+  const div = createDiv(t);
+  const anim = div.animate(null, {pseudoElement: '::before'});
+  assert_class_string(anim, 'Animation', 'The returned object is an Animation');
+}, 'animate() with pseudoElement parameter without content creates an Animation object');
+
 test(t => {
   const div = createDiv(t);
   div.classList.add('pseudo');
   div.style.display = 'list-item';
+  getComputedStyle(div,"::marker").content; // Sync style
   const anim = div.animate(null, {pseudoElement: '::marker'});
   assert_class_string(anim, 'Animation', 'The returned object is an Animation for ::marker');
 }, 'animate() with pseudoElement parameter  creates an Animation object for ::marker');
@@ -268,31 +278,45 @@
 test(t => {
   const div = createDiv(t);
   div.classList.add('pseudo');
+  getComputedStyle(div,"::before").content; // Sync style
   const anim = div.animate(null, {pseudoElement: '::before'});
+  assert_equals(anim.effect.target, div, 'The returned element has the correct target element');
   assert_equals(anim.effect.pseudoElement, '::before',
-                'The returned Animation targets to the correct selector');
+                'The returned Animation targets the correct selector');
 }, 'animate() with pseudoElement an Animation object targeting ' +
-   'to the correct pseudo-element');
+   'the correct pseudo-element');
+
+test(t => {
+  const div = createDiv(t);
+  const anim = div.animate(null, {pseudoElement: '::before'});
+  assert_equals(anim.effect.target, div, 'The returned element has the correct target element');
+  assert_equals(anim.effect.pseudoElement, '::before',
+                'The returned Animation targets the correct selector');
+}, 'animate() with pseudoElement without content creates an Animation object targeting ' +
+   'the correct pseudo-element');
 
 test(t => {
   const div = createDiv(t);
   div.classList.add('pseudo');
   div.style.display = 'list-item';
+  getComputedStyle(div,"::marker").content; // Sync style
   const anim = div.animate(null, {pseudoElement: '::marker'});
+  assert_equals(anim.effect.target, div, 'The returned element has the correct target element');
   assert_equals(anim.effect.pseudoElement, '::marker',
-                'The returned Animation targets to the correct selector');
+                'The returned Animation targets the correct selector');
 }, 'animate() with pseudoElement an Animation object targeting ' +
-   'to the correct pseudo-element for ::marker');
+   'the correct pseudo-element for ::marker');
 
 test(t => {
   const div = createDiv(t);
   div.classList.add('pseudo');
   div.textContent = 'foo';
   const anim = div.animate(null, {pseudoElement: '::first-line'});
+  assert_equals(anim.effect.target, div, 'The returned element has the correct target element');
   assert_equals(anim.effect.pseudoElement, '::first-line',
-                'The returned Animation targets to the correct selector');
+                'The returned Animation targets the correct selector');
 }, 'animate() with pseudoElement an Animation object targeting ' +
-   'to the correct pseudo-element for ::first-line');
+   'the correct pseudo-element for ::first-line');
 
 </script>
 </body>
diff --git a/tests/wpt/web-platform-tests/web-animations/interfaces/KeyframeEffect/target.html b/tests/wpt/web-platform-tests/web-animations/interfaces/KeyframeEffect/target.html
index 10f42eea4e5b..a9827d64d3d0 100644
--- a/tests/wpt/web-platform-tests/web-animations/interfaces/KeyframeEffect/target.html
+++ b/tests/wpt/web-platform-tests/web-animations/interfaces/KeyframeEffect/target.html
@@ -1,11 +1,17 @@
 <!DOCTYPE html>
 <meta charset=utf-8>
-<title>KeyframeEffect.target</title>
+<title>KeyframeEffect.target and .pseudoElement</title>
 <link rel="help"
   href="https://drafts.csswg.org/web-animations/#dom-keyframeeffect-target">
 <script src="/resources/testharness.js"></script>
 <script src="/resources/testharnessreport.js"></script>
 <script src="../../testcommon.js"></script>
+<style>
+  .before::before {content: 'foo'; display: inline-block;}
+  .after::after {content: 'bar'; display: inline-block;}
+  .pseudoa::before, .pseudoc::before {margin-left: 10px;}
+  .pseudob::before, .pseudoc::after {margin-left: 20px;}
+</style>
 <body>
 <div id="log"></div>
 <script>
@@ -105,5 +111,151 @@
   await waitForNextFrame();
 }, 'Target element can be set to a foreign element');
 
+// Pseudo-element tests
+// (testing target and pseudoElement in these cases)
+// Since blink uses separate code paths for handling pseudo-element styles
+// depending on whether content is set (putting the pseudo-element in the layout),
+// we run tests on both cases.
+for (const hasContent of [true, false]){
+  test(t => {
+    const d = createDiv(t);
+    d.classList.add('pseudoa');
+    if (hasContent) {
+      d.classList.add('before');
+      getComputedStyle(d,"::before").content; // Sync style
+    }
+
+    const effect = new KeyframeEffect(null, gKeyFrames, 100 * MS_PER_SEC);
+    const anim = new Animation(effect, document.timeline);
+    anim.play();
+
+    anim.currentTime = 50 * MS_PER_SEC;
+    assert_equals(getComputedStyle(d, '::before').marginLeft, '10px',
+                  'Value at 50% progress before setting new target');
+    effect.target = d;
+    effect.pseudoElement = '::before';
+
+    assert_equals(effect.target, d, "Target element is set correctly");
+    assert_equals(effect.pseudoElement, '::before', "Target pseudo-element set correctly");
+    assert_equals(getComputedStyle(d, '::before').marginLeft, '50px',
+                  'Value at 50% progress after setting new target');
+  }, "Change target from null to " + (hasContent ? "an existing" : "a non-existing") +
+     " pseudoElement setting target first.");
+
+  test(t => {
+    const d = createDiv(t);
+    d.classList.add('pseudoa');
+    if (hasContent) {
+      d.classList.add('before');
+      getComputedStyle(d,"::before").content; // Sync style
+    }
+
+    const effect = new KeyframeEffect(null, gKeyFrames, 100 * MS_PER_SEC);
+    const anim = new Animation(effect, document.timeline);
+    anim.play();
+
+    anim.currentTime = 50 * MS_PER_SEC;
+    assert_equals(getComputedStyle(d, '::before').marginLeft, '10px',
+                  'Value at 50% progress before setting new target');
+    effect.pseudoElement = '::before';
+    effect.target = d;
+
+    assert_equals(effect.target, d, "Target element is set correctly");
+    assert_equals(effect.pseudoElement, '::before', "Target pseudo-element set correctly");
+    assert_equals(getComputedStyle(d, '::before').marginLeft, '50px',
+                  'Value at 50% progress after setting new target');
+  }, "Change target from null to " + (hasContent ? "an existing" : "a non-existing") +
+     " pseudoElement setting pseudoElement first.");
+
+  test(t => {
+    const d = createDiv(t);
+    d.classList.add('pseudoa');
+    if (hasContent) {
+      d.classList.add('before');
+      getComputedStyle(d,"::before").content; // Sync style
+    }
+    const anim = d.animate(gKeyFrames, {duration: 100 * MS_PER_SEC, pseudoElement: '::before'});
+
+    anim.currentTime = 50 * MS_PER_SEC;
+    anim.effect.pseudoElement = null;
+    assert_equals(anim.effect.target, d,
+                  "Animation targets specified element (target element)");
+    assert_equals(anim.effect.pseudoElement, null,
+                  "Animation targets specified element (null pseudo-selector)");
+    assert_equals(getComputedStyle(d, '::before').marginLeft, '10px',
+                  'Value of 1st element (currently not targeted) after ' +
+                  'changing the effect target');
+    assert_equals(getComputedStyle(d).marginLeft, '50px',
+                  'Value of 2nd element (currently targeted) after ' +
+                  'changing the effect target');
+  }, "Change target from " + (hasContent ? "an existing" : "a non-existing") + " pseudo-element to the originating element.");
+
+  for (const prevHasContent of [true, false]) {
+    test(t => {
+      const a = createDiv(t);
+      a.classList.add('pseudoa');
+      const b = createDiv(t);
+      b.classList.add('pseudob');
+      if (prevHasContent) {
+        a.classList.add('before');
+        getComputedStyle(a,"::before").content; // Sync style
+      }
+      if (hasContent) {
+        b.classList.add('before');
+        getComputedStyle(b,"::before").content; // Sync style
+      }
+
+      const anim = a.animate(gKeyFrames, {duration: 100 * MS_PER_SEC, pseudoElement: '::before'});
+
+      anim.currentTime = 50 * MS_PER_SEC;
+      anim.effect.target = b;
+      assert_equals(anim.effect.target, b,
+                    "Animation targets specified pseudo-element (target element)");
+      assert_equals(anim.effect.pseudoElement, '::before',
+                    "Animation targets specified pseudo-element (pseudo-selector)");
+      assert_equals(getComputedStyle(a, '::before').marginLeft, '10px',
+                    'Value of 1st element (currently not targeted) after ' +
+                    'changing the effect target');
+      assert_equals(getComputedStyle(b, '::before').marginLeft, '50px',
+                    'Value of 2nd element (currently targeted) after ' +
+                    'changing the effect target');
+    }, "Change target from " + (prevHasContent ? "an existing" : "a non-existing") +
+        " to a different " + (hasContent ? "existing" : "non-existing") +
+        " pseudo-element by setting target.");
+
+    test(t => {
+      const d = createDiv(t);
+      d.classList.add('pseudoc');
+      if (prevHasContent) {
+        d.classList.add('before');
+        getComputedStyle(d,"::before").content; // Sync style
+      }
+      if (hasContent) {
+        d.classList.add('after');
+        getComputedStyle(d,"::after").content; // Sync style
+      }
+
+      const anim = d.animate(gKeyFrames, {duration: 100 * MS_PER_SEC, pseudoElement: '::before'});
+
+      anim.currentTime = 50 * MS_PER_SEC;
+      anim.effect.pseudoElement = '::after';
+      assert_equals(anim.effect.target, d,
+                    "Animation targets specified pseudo-element (target element)");
+      assert_equals(anim.effect.pseudoElement, '::after',
+                    "Animation targets specified pseudo-element (pseudo-selector)");
+      assert_equals(getComputedStyle(d, '::before').marginLeft, '10px',
+                    'Value of 1st element (currently not targeted) after ' +
+                    'changing the effect target');
+      assert_equals(getComputedStyle(d, '::after').marginLeft, '50px',
+                    'Value of 2nd element (currently targeted) after ' +
+                    'changing the effect target');
+    }, "Change target from " + (prevHasContent ? "an existing" : "a non-existing") +
+        " to a different " + (hasContent ? "existing" : "non-existing") +
+        " pseudo-element by setting pseudoElement.");
+  }
+}
+
+
+
 </script>
 </body>
diff --git a/tests/wpt/web-platform-tests/webaudio/the-audio-api/the-audioworklet-interface/audioworkletglobalscope-sample-rate.https.html b/tests/wpt/web-platform-tests/webaudio/the-audio-api/the-audioworklet-interface/audioworkletglobalscope-sample-rate.https.html
index d87e35b571d7..84458d0aaa77 100644
--- a/tests/wpt/web-platform-tests/webaudio/the-audio-api/the-audioworklet-interface/audioworkletglobalscope-sample-rate.https.html
+++ b/tests/wpt/web-platform-tests/webaudio/the-audio-api/the-audioworklet-interface/audioworkletglobalscope-sample-rate.https.html
@@ -12,30 +12,32 @@
     <script id="layout-test-code">
       let audit = Audit.createTaskRunner();
 
-      let sampleRate = 48000;
-      let renderLength = 512;
-      let context = new OfflineAudioContext(1, renderLength, sampleRate);
+      setup(() => {
+        let sampleRate = 48000;
+        let renderLength = 512;
+        let context = new OfflineAudioContext(1, renderLength, sampleRate);
 
-      let filePath = 'processors/one-pole-processor.js';
+        let filePath = 'processors/one-pole-processor.js';
 
-      // Without rendering the context, attempt to access |sampleRate| in the
-      // global scope as soon as it is created.
-      audit.define(
-          'Query |sampleRate| upon AudioWorkletGlobalScope construction',
-          (task, should) => {
-            let onePoleFilterNode =
-                new AudioWorkletNode(context, 'one-pole-filter');
-            let frequencyParam = onePoleFilterNode.parameters.get('frequency');
+        // Without rendering the context, attempt to access |sampleRate| in the
+        // global scope as soon as it is created.
+        audit.define(
+            'Query |sampleRate| upon AudioWorkletGlobalScope construction',
+            (task, should) => {
+              let onePoleFilterNode =
+                  new AudioWorkletNode(context, 'one-pole-filter');
+              let frequencyParam = onePoleFilterNode.parameters.get('frequency');
 
-            should(frequencyParam.maxValue,
-                   'frequencyParam.maxValue')
-                .beEqualTo(0.5 * context.sampleRate);
+              should(frequencyParam.maxValue,
+                     'frequencyParam.maxValue')
+                  .beEqualTo(0.5 * context.sampleRate);
 
-            task.done();
-          });
+              task.done();
+            });
 
-      context.audioWorklet.addModule(filePath).then(() => {
-        audit.run();
+        context.audioWorklet.addModule(filePath).then(() => {
+          audit.run();
+        });
       });
     </script>
   </body>
diff --git a/tests/wpt/web-platform-tests/webaudio/the-audio-api/the-audioworklet-interface/audioworkletglobalscope-timing-info.https.html b/tests/wpt/web-platform-tests/webaudio/the-audio-api/the-audioworklet-interface/audioworkletglobalscope-timing-info.https.html
index 79d402c51862..5f4bee7c5312 100644
--- a/tests/wpt/web-platform-tests/webaudio/the-audio-api/the-audioworklet-interface/audioworkletglobalscope-timing-info.https.html
+++ b/tests/wpt/web-platform-tests/webaudio/the-audio-api/the-audioworklet-interface/audioworkletglobalscope-timing-info.https.html
@@ -12,45 +12,47 @@
     <script id="layout-test-code">
       let audit = Audit.createTaskRunner();
 
-      let sampleRate = 48000;
-      let renderLength = 512;
-      let context = new OfflineAudioContext(1, renderLength, sampleRate);
+      setup(() => {
+        let sampleRate = 48000;
+        let renderLength = 512;
+        let context = new OfflineAudioContext(1, renderLength, sampleRate);
 
-      let filePath = 'processors/timing-info-processor.js';
+        let filePath = 'processors/timing-info-processor.js';
 
-      audit.define(
-          'Check the timing information from AudioWorkletProcessor',
-          (task, should) => {
-            let portWorkletNode =
-                new AudioWorkletNode(context, 'timing-info-processor');
-            portWorkletNode.connect(context.destination);
+        audit.define(
+            'Check the timing information from AudioWorkletProcessor',
+            (task, should) => {
+              let portWorkletNode =
+                  new AudioWorkletNode(context, 'timing-info-processor');
+              portWorkletNode.connect(context.destination);
 
-            // Suspend at render quantum boundary and check the timing
-            // information between the main thread and the rendering thread.
-            [0, 128, 256, 384].map((suspendFrame) => {
-              context.suspend(suspendFrame/sampleRate).then(() => {
-                portWorkletNode.port.onmessage = (event) => {
-                  should(event.data.currentFrame,
-                         'currentFrame from the processor at ' + suspendFrame)
-                      .beEqualTo(suspendFrame);
-                  should(event.data.currentTime,
-                         'currentTime from the processor at '
-                             + context.currentTime)
-                      .beEqualTo(context.currentTime);
-                  context.resume();
-                };
+              // Suspend at render quantum boundary and check the timing
+              // information between the main thread and the rendering thread.
+              [0, 128, 256, 384].map((suspendFrame) => {
+                context.suspend(suspendFrame/sampleRate).then(() => {
+                  portWorkletNode.port.onmessage = (event) => {
+                    should(event.data.currentFrame,
+                           'currentFrame from the processor at ' + suspendFrame)
+                        .beEqualTo(suspendFrame);
+                    should(event.data.currentTime,
+                           'currentTime from the processor at '
+                               + context.currentTime)
+                        .beEqualTo(context.currentTime);
+                    context.resume();
+                  };
 
-                portWorkletNode.port.postMessage('query-timing-info');
+                  portWorkletNode.port.postMessage('query-timing-info');
+                });
               });
-            });
 
-            context.startRendering().then(() => {
-              task.done();
+              context.startRendering().then(() => {
+                task.done();
+              });
             });
-          });
 
-      context.audioWorklet.addModule(filePath).then(() => {
-        audit.run();
+        context.audioWorklet.addModule(filePath).then(() => {
+          audit.run();
+        });
       });
     </script>
   </body>
diff --git a/tests/wpt/web-platform-tests/webaudio/the-audio-api/the-audioworklet-interface/audioworkletnode-onerror.https.html b/tests/wpt/web-platform-tests/webaudio/the-audio-api/the-audioworklet-interface/audioworkletnode-onerror.https.html
index 0a9966add85c..0914edbb3b0a 100644
--- a/tests/wpt/web-platform-tests/webaudio/the-audio-api/the-audioworklet-interface/audioworkletnode-onerror.https.html
+++ b/tests/wpt/web-platform-tests/webaudio/the-audio-api/the-audioworklet-interface/audioworkletnode-onerror.https.html
@@ -12,43 +12,45 @@
     <script id="layout-test-code">
       let audit = Audit.createTaskRunner();
 
-      const sampleRate = 48000;
-      const renderLength = sampleRate * 0.1;
-      let context = new OfflineAudioContext(1, renderLength, sampleRate);
+      setup(() => {
+        const sampleRate = 48000;
+        const renderLength = sampleRate * 0.1;
+        let context = new OfflineAudioContext(1, renderLength, sampleRate);
 
-      let filePath = 'processors/error-processor.js';
+        let filePath = 'processors/error-processor.js';
 
-      // Test |onprocessorerror| called upon failure of processor constructor.
-      audit.define('constructor-error',
-          (task, should) => {
-            let constructorErrorWorkletNode =
-                new AudioWorkletNode(context, 'constructor-error');
-            constructorErrorWorkletNode.onprocessorerror = () => {
-              // Without 'processorerror' event callback, this test will be
-              // timed out.
-              task.done();
-            };
-          });
+        // Test |onprocessorerror| called upon failure of processor constructor.
+        audit.define('constructor-error',
+            (task, should) => {
+              let constructorErrorWorkletNode =
+                  new AudioWorkletNode(context, 'constructor-error');
+              constructorErrorWorkletNode.onprocessorerror = () => {
+                // Without 'processorerror' event callback, this test will be
+                // timed out.
+                task.done();
+              };
+            });
 
-      // Test |onprocessorerror| called upon failure of process() method.
-      audit.define('process-error',
-          (task, should) => {
-            let processErrorWorkletNode =
-                new AudioWorkletNode(context, 'process-error');
-            processErrorWorkletNode.connect(context.destination);
-            processErrorWorkletNode.onprocessorerror = () => {
-              // Without 'processorerror' event callback, this test will be
-              // timed out.
-              task.done();
-            };
+        // Test |onprocessorerror| called upon failure of process() method.
+        audit.define('process-error',
+            (task, should) => {
+              let processErrorWorkletNode =
+                  new AudioWorkletNode(context, 'process-error');
+              processErrorWorkletNode.connect(context.destination);
+              processErrorWorkletNode.onprocessorerror = () => {
+                // Without 'processorerror' event callback, this test will be
+                // timed out.
+                task.done();
+              };
 
-            context.startRendering();
-          });
+              context.startRendering();
+            });
 
-      // 'error-processor.js' contains 2 class definitions represents an error
-      // in the constructor and an error in the process method respectively.
-      context.audioWorklet.addModule(filePath).then(() => {
-        audit.run();
+        // 'error-processor.js' contains 2 class definitions represents an error
+        // in the constructor and an error in the process method respectively.
+        context.audioWorklet.addModule(filePath).then(() => {
+          audit.run();
+        });
       });
     </script>
   </body>
diff --git a/tests/wpt/web-platform-tests/webaudio/the-audio-api/the-audioworklet-interface/audioworkletnode-output-channel-count.https.html b/tests/wpt/web-platform-tests/webaudio/the-audio-api/the-audioworklet-interface/audioworkletnode-output-channel-count.https.html
index 9d65d872b987..a8a7f5ed1de7 100644
--- a/tests/wpt/web-platform-tests/webaudio/the-audio-api/the-audioworklet-interface/audioworkletnode-output-channel-count.https.html
+++ b/tests/wpt/web-platform-tests/webaudio/the-audio-api/the-audioworklet-interface/audioworkletnode-output-channel-count.https.html
@@ -13,7 +13,7 @@
       const audit = Audit.createTaskRunner();
       const context = new AudioContext();
 
-      (async function () {
+      setup(async function () {
         await context.audioWorklet.addModule(
             'processors/channel-count-processor.js');
 
@@ -76,7 +76,7 @@
             });
 
         audit.run();
-      })();
+      });
     </script>
   </body>
 </html>
diff --git a/tests/wpt/web-platform-tests/webaudio/the-audio-api/the-mediaelementaudiosourcenode-interface/cors-check.https.html b/tests/wpt/web-platform-tests/webaudio/the-audio-api/the-mediaelementaudiosourcenode-interface/cors-check.https.html
index a2fa8040b2c6..38bd94a037c3 100644
--- a/tests/wpt/web-platform-tests/webaudio/the-audio-api/the-mediaelementaudiosourcenode-interface/cors-check.https.html
+++ b/tests/wpt/web-platform-tests/webaudio/the-audio-api/the-mediaelementaudiosourcenode-interface/cors-check.https.html
@@ -14,60 +14,62 @@
     <script id="layout-test-code">
       const audit = Audit.createTaskRunner();
 
-      const context = new AudioContext();
-      context.suspend();
+      setup(() => {
+        const context = new AudioContext();
+        context.suspend();
 
-      const host_info = get_host_info();
-      const audioElement = document.createElement('audio');
-      audioElement.loop = true;
-      audioElement.crossOrigin = 'anonymous';
-      const wav =
-          host_info.HTTPS_ORIGIN + '/webaudio/resources/4ch-440.wav?' +
-          'pipe=header(access-control-allow-origin,*)';
-      audioElement.src =
-          host_info.HTTPS_REMOTE_ORIGIN +
-          '/fetch/api/resources/redirect.py?location=' +
-          encodeURIComponent(wav);
-      let source;
-      let workletRecorder;
+        const host_info = get_host_info();
+        const audioElement = document.createElement('audio');
+        audioElement.loop = true;
+        audioElement.crossOrigin = 'anonymous';
+        const wav =
+            host_info.HTTPS_ORIGIN + '/webaudio/resources/4ch-440.wav?' +
+            'pipe=header(access-control-allow-origin,*)';
+        audioElement.src =
+            host_info.HTTPS_REMOTE_ORIGIN +
+            '/fetch/api/resources/redirect.py?location=' +
+            encodeURIComponent(wav);
+        let source;
+        let workletRecorder;
 
-      audit.define(
-          {label: 'setting-up-graph'},
-          (task, should) => {
-            source = new MediaElementAudioSourceNode(context, {
-              mediaElement: audioElement
+        audit.define(
+            {label: 'setting-up-graph'},
+            (task, should) => {
+              source = new MediaElementAudioSourceNode(context, {
+                mediaElement: audioElement
+              });
+              workletRecorder = new AudioWorkletNode(
+                  context, 'recorder-processor', {channelCount: 4});
+              source.connect(workletRecorder).connect(context.destination);
+              task.done();
             });
-            workletRecorder = new AudioWorkletNode(
-                context, 'recorder-processor', {channelCount: 4});
-            source.connect(workletRecorder).connect(context.destination);
-            task.done();
-          });
 
-      // The recorded data from MESN must be non-zero. The source file contains
-      // 4 channels of sine wave.
-      audit.define(
-          {label: 'start-playback-and-capture'},
-          (task, should) => {
-            workletRecorder.port.onmessage = (event) => {
-              if (event.data.type === 'recordfinished') {
-                for (let i = 0; i < event.data.recordBuffer.length; ++i) {
-                  const channelData = event.data.recordBuffer[i];
-                  should(channelData, `Recorded channel #${i}`)
-                      .notBeConstantValueOf(0);
+        // The recorded data from MESN must be non-zero. The source file contains
+        // 4 channels of sine wave.
+        audit.define(
+            {label: 'start-playback-and-capture'},
+            (task, should) => {
+              workletRecorder.port.onmessage = (event) => {
+                if (event.data.type === 'recordfinished') {
+                  for (let i = 0; i < event.data.recordBuffer.length; ++i) {
+                    const channelData = event.data.recordBuffer[i];
+                    should(channelData, `Recorded channel #${i}`)
+                        .notBeConstantValueOf(0);
+                  }
                 }
-              }
 
-              task.done();
-            };
+                task.done();
+              };
 
-            context.resume();
-            audioElement.play();
-          });
+              context.resume();
+              audioElement.play();
+            });
 
-      Promise.all([
-        context.audioWorklet.addModule('/webaudio/js/worklet-recorder.js')
-      ]).then(() => {
-        audit.run();
+        Promise.all([
+          context.audioWorklet.addModule('/webaudio/js/worklet-recorder.js')
+        ]).then(() => {
+          audit.run();
+        });
       });
     </script>
   </body>
diff --git a/tests/wpt/web-platform-tests/webaudio/the-audio-api/the-mediaelementaudiosourcenode-interface/no-cors.https.html b/tests/wpt/web-platform-tests/webaudio/the-audio-api/the-mediaelementaudiosourcenode-interface/no-cors.https.html
index 38324a9f67a6..de2f0b7dd3b6 100644
--- a/tests/wpt/web-platform-tests/webaudio/the-audio-api/the-mediaelementaudiosourcenode-interface/no-cors.https.html
+++ b/tests/wpt/web-platform-tests/webaudio/the-audio-api/the-mediaelementaudiosourcenode-interface/no-cors.https.html
@@ -14,59 +14,61 @@
     <script id="layout-test-code">
       const audit = Audit.createTaskRunner();
 
-      const context = new AudioContext();
-      context.suspend();
+      setup(() => {
+        const context = new AudioContext();
+        context.suspend();
 
-      const host_info = get_host_info();
-      const audioElement = document.createElement('audio');
-      audioElement.loop = true;
-      const wav =
-          host_info.HTTPS_ORIGIN + '/webaudio/resources/4ch-440.wav?' +
-          'pipe=header(access-control-allow-origin,*)';
-      audioElement.src =
-          host_info.HTTPS_REMOTE_ORIGIN +
-          '/fetch/api/resources/redirect.py?location=' +
-          encodeURIComponent(wav);
-      let source;
-      let workletRecorder;
+        const host_info = get_host_info();
+        const audioElement = document.createElement('audio');
+        audioElement.loop = true;
+        const wav =
+            host_info.HTTPS_ORIGIN + '/webaudio/resources/4ch-440.wav?' +
+            'pipe=header(access-control-allow-origin,*)';
+        audioElement.src =
+            host_info.HTTPS_REMOTE_ORIGIN +
+            '/fetch/api/resources/redirect.py?location=' +
+            encodeURIComponent(wav);
+        let source;
+        let workletRecorder;
 
-      audit.define(
-          {label: 'setting-up-graph'},
-          (task, should) => {
-            source = new MediaElementAudioSourceNode(context, {
-              mediaElement: audioElement
+        audit.define(
+            {label: 'setting-up-graph'},
+            (task, should) => {
+              source = new MediaElementAudioSourceNode(context, {
+                mediaElement: audioElement
+              });
+              workletRecorder = new AudioWorkletNode(
+                  context, 'recorder-processor', {channelCount: 4});
+              source.connect(workletRecorder).connect(context.destination);
+              task.done();
             });
-            workletRecorder = new AudioWorkletNode(
-                context, 'recorder-processor', {channelCount: 4});
-            source.connect(workletRecorder).connect(context.destination);
-            task.done();
-          });
 
-      // The recorded data from MESN must be non-zero. The source file contains
-      // 4 channels of sine wave.
-      audit.define(
-          {label: 'start-playback-and-capture'},
-          (task, should) => {
-            workletRecorder.port.onmessage = (event) => {
-              if (event.data.type === 'recordfinished') {
-                for (let i = 0; i < event.data.recordBuffer.length; ++i) {
-                  const channelData = event.data.recordBuffer[i];
-                  should(channelData, `Recorded channel #${i}`)
-                      .beConstantValueOf(0);
+        // The recorded data from MESN must be non-zero. The source file contains
+        // 4 channels of sine wave.
+        audit.define(
+            {label: 'start-playback-and-capture'},
+            (task, should) => {
+              workletRecorder.port.onmessage = (event) => {
+                if (event.data.type === 'recordfinished') {
+                  for (let i = 0; i < event.data.recordBuffer.length; ++i) {
+                    const channelData = event.data.recordBuffer[i];
+                    should(channelData, `Recorded channel #${i}`)
+                        .beConstantValueOf(0);
+                  }
                 }
-              }
 
-              task.done();
-            };
+                task.done();
+              };
 
-            context.resume();
-            audioElement.play();
-          });
+              context.resume();
+              audioElement.play();
+            });
 
-      Promise.all([
-        context.audioWorklet.addModule('/webaudio/js/worklet-recorder.js')
-      ]).then(() => {
-        audit.run();
+        Promise.all([
+          context.audioWorklet.addModule('/webaudio/js/worklet-recorder.js')
+        ]).then(() => {
+          audit.run();
+        });
       });
     </script>
   </body>
diff --git a/tests/wpt/web-platform-tests/webauthn/resources/common-inputs.js b/tests/wpt/web-platform-tests/webauthn/resources/common-inputs.js
new file mode 100644
index 000000000000..8370f7f079a0
--- /dev/null
+++ b/tests/wpt/web-platform-tests/webauthn/resources/common-inputs.js
@@ -0,0 +1,34 @@
+const ES256_ID = -7;
+const CHALLENGE = "climb the mountain";
+
+const PUBLIC_KEY_RP = {
+    id: window.location.hostname,
+    name: "Example RP",
+};
+
+const PUBLIC_KEY_USER = {
+    id: new TextEncoder().encode("123456789"),
+    name: "madeline@example.com",
+    displayName: "Madeline",
+    icon: "https://example.com/celeste.png"
+};
+
+// ES256.
+const PUBLIC_KEY_PARAMETERS =  [{
+    type: "public-key",
+    alg: ES256_ID,
+}];
+
+const AUTHENTICATOR_SELECTION_CRITERIA = {
+    requireResidentKey: false,
+    userVerification: "discouraged",
+};
+
+const MAKE_CREDENTIAL_OPTIONS = {
+    challenge: new TextEncoder("utf-8").encode(CHALLENGE),
+    rp: PUBLIC_KEY_RP,
+    user: PUBLIC_KEY_USER,
+    pubKeyCredParams: PUBLIC_KEY_PARAMETERS,
+    authenticatorSelection: AUTHENTICATOR_SELECTION_CRITERIA,
+    excludeCredentials: [],
+};
diff --git a/tests/wpt/web-platform-tests/webauthn/resources/utils.js b/tests/wpt/web-platform-tests/webauthn/resources/utils.js
new file mode 100644
index 000000000000..f361a94d2e4f
--- /dev/null
+++ b/tests/wpt/web-platform-tests/webauthn/resources/utils.js
@@ -0,0 +1,335 @@
+"use strict";
+
+// Encodes |data| into base64url string. There is no '=' padding, and the
+// characters '-' and '_' must be used instead of '+' and '/', respectively.
+function base64urlEncode(data) {
+  let result = btoa(data);
+  return result.replace(/=+$/g, '').replace(/\+/g, "-").replace(/\//g, "_");
+}
+
+// Decode |encoded| using base64url decoding.
+function base64urlDecode(encoded) {
+  return atob(encoded.replace(/\-/g, "+").replace(/\_/g, "/"));
+}
+
+// Encodes a Uint8Array as a base64url string.
+function uint8ArrayToBase64url(array) {
+  return base64urlEncode(String.fromCharCode.apply(null, array));
+}
+
+// Convert a EC signature from DER to a concatenation of the r and s parameters,
+// as expected by the subtle crypto API.
+function convertDERSignatureToSubtle(der) {
+  let index = -1;
+  const SEQUENCE = 0x30;
+  const INTEGER = 0x02;
+  assert_equals(der[++index], SEQUENCE);
+
+  let size = der[++index];
+  assert_equals(size + 2, der.length);
+
+  assert_equals(der[++index], INTEGER);
+  let rSize = der[++index];
+  ++index;
+  while (der[index] == 0) {
+    ++index;
+    --rSize;
+  }
+  let r = der.slice(index, index + rSize);
+  index += rSize;
+
+  assert_equals(der[index], INTEGER);
+  let sSize = der[++index];
+  ++index;
+  while (der[index] == 0) {
+    ++index;
+    --sSize;
+  }
+  let s = der.slice(index, index + sSize);
+  assert_equals(index + sSize, der.length);
+
+  let result = new Uint8Array(64);
+  result.set(r, 32 - rSize);
+  result.set(s, 64 - sSize);
+  return result;
+};
+
+function coseObjectToJWK(cose) {
+  // Convert an object representing a COSE_Key encoded public key into a JSON
+  // Web Key object.
+  // https://tools.ietf.org/html/rfc7517
+
+  // The example used on the test is a ES256 key, so we only implement that.
+  let jwk = {};
+  if (cose.type != 2)
+    assert_unreached("Unknown type: " + cose.type);
+
+  jwk.kty = "EC";
+  if (cose.alg != ES256_ID)
+    assert_unreached("Unknown alg: " + cose.alg);
+
+  if (cose.crv != 1)
+    assert_unreached("Unknown curve: " + jwk.crv);
+
+  jwk.crv = "P-256";
+  jwk.x = uint8ArrayToBase64url(cose.x);
+  jwk.y = uint8ArrayToBase64url(cose.y);
+  return jwk;
+}
+
+function parseCosePublicKey(coseKey) {
+  // Parse a CTAP2 canonical CBOR encoding form key.
+  // https://fidoalliance.org/specs/fido-v2.0-id-20180227/fido-client-to-authenticator-protocol-v2.0-id-20180227.html#ctap2-canonical-cbor-encoding-form
+  let parsed = new Cbor(coseKey);
+  let cbor = parsed.getCBOR();
+  let key = {
+    type: cbor[1],
+    alg: cbor[3],
+  };
+  if (key.type != 2)
+    assert_unreached("Unknown key type: " + key.type);
+
+  key.crv = cbor[-1];
+  key.x = new Uint8Array(cbor[-2]);
+  key.y = new Uint8Array(cbor[-3]);
+  return key;
+}
+
+function parseAttestedCredentialData(attestedCredentialData) {
+  // Parse the attested credential data according to
+  // https://w3c.github.io/webauthn/#attested-credential-data
+  let aaguid = attestedCredentialData.slice(0, 16);
+  let credentialIdLength = (attestedCredentialData[16] << 8)
+                         + attestedCredentialData[17];
+  let credentialId =
+      attestedCredentialData.slice(18, 18 + credentialIdLength);
+  let credentialPublicKey = parseCosePublicKey(
+      attestedCredentialData.slice(18 + credentialIdLength,
+                                   attestedCredentialData.length));
+
+  return { aaguid, credentialIdLength, credentialId, credentialPublicKey };
+}
+
+function parseAuthenticatorData(authenticatorData) {
+  // Parse the authenticator data according to
+  // https://w3c.github.io/webauthn/#sctn-authenticator-data
+  assert_greater_than_equal(authenticatorData.length, 37);
+  let flags = authenticatorData[32];
+  let counter = authenticatorData.slice(33, 37);
+
+  let attestedCredentialData = authenticatorData.length > 37 ?
+        parseAttestedCredentialData(authenticatorData.slice(37)) : null;
+  let extensions = null;
+  if (attestedCredentialData &&
+      authenticatorData.length > 37 + attestedCredentialData.length) {
+    extensions = authenticatorData.slice(37 + attestedCredentialData.length);
+  }
+
+  return {
+    rpIdHash: authenticatorData.slice(0, 32),
+    flags: {
+      up: !!(flags & 0x01),
+      uv: !!(flags & 0x04),
+      at: !!(flags & 0x40),
+      ed: !!(flags & 0x80),
+    },
+    counter: (counter[0] << 24)
+           + (counter[1] << 16)
+           + (counter[2] << 8)
+           + counter[3],
+    attestedCredentialData,
+    extensions,
+  };
+}
+
+// Taken from
+// https://cs.chromium.org/chromium/src/chrome/browser/resources/cryptotoken/cbor.js?rcl=c9b6055cf9c158fb4119afd561a591f8fc95aefe
+class Cbor {
+  constructor(buffer) {
+    this.slice = new Uint8Array(buffer);
+  }
+  get data() {
+    return this.slice;
+  }
+  get length() {
+    return this.slice.length;
+  }
+  get empty() {
+    return this.slice.length == 0;
+  }
+  get hex() {
+    const hexTable = '0123456789abcdef';
+    let s = '';
+    for (let i = 0; i < this.data.length; i++) {
+      s += hexTable.charAt(this.data[i] >> 4);
+      s += hexTable.charAt(this.data[i] & 15);
+    }
+    return s;
+  }
+  compare(other) {
+    if (this.length < other.length) {
+      return -1;
+    } else if (this.length > other.length) {
+      return 1;
+    }
+    for (let i = 0; i < this.length; i++) {
+      if (this.slice[i] < other.slice[i]) {
+        return -1;
+      } else if (this.slice[i] > other.slice[i]) {
+        return 1;
+      }
+    }
+    return 0;
+  }
+  getU8() {
+    if (this.empty) {
+      throw('Cbor: empty during getU8');
+    }
+    const byte = this.slice[0];
+    this.slice = this.slice.subarray(1);
+    return byte;
+  }
+  skip(n) {
+    if (this.length < n) {
+      throw('Cbor: too few bytes to skip');
+    }
+    this.slice = this.slice.subarray(n);
+  }
+  getBytes(n) {
+    if (this.length < n) {
+      throw('Cbor: insufficient bytes in getBytes');
+    }
+    const ret = this.slice.subarray(0, n);
+    this.slice = this.slice.subarray(n);
+    return ret;
+  }
+  getCBORHeader() {
+    const copy = new Cbor(this.slice);
+    const a = this.getU8();
+    const majorType = a >> 5;
+    const info = a & 31;
+    if (info < 24) {
+      return [majorType, info, new Cbor(copy.getBytes(1))];
+    } else if (info < 28) {
+      const lengthLength = 1 << (info - 24);
+      let data = this.getBytes(lengthLength);
+      let value = 0;
+      for (let i = 0; i < lengthLength; i++) {
+        // Javascript has problems handling uint64s given the limited range of
+        // a double.
+        if (value > 35184372088831) {
+          throw('Cbor: cannot represent CBOR number');
+        }
+        // Not using bitwise operations to avoid truncating to 32 bits.
+        value *= 256;
+        value += data[i];
+      }
+      switch (lengthLength) {
+        case 1:
+          if (value < 24) {
+            throw('Cbor: value should have been encoded in single byte');
+          }
+          break;
+        case 2:
+          if (value < 256) {
+            throw('Cbor: non-minimal integer');
+          }
+          break;
+        case 4:
+          if (value < 65536) {
+            throw('Cbor: non-minimal integer');
+          }
+          break;
+        case 8:
+          if (value < 4294967296) {
+            throw('Cbor: non-minimal integer');
+          }
+          break;
+      }
+      return [majorType, value, new Cbor(copy.getBytes(1 + lengthLength))];
+    } else {
+      throw('Cbor: CBOR contains unhandled info value ' + info);
+    }
+  }
+  getCBOR() {
+    const [major, value] = this.getCBORHeader();
+    switch (major) {
+      case 0:
+        return value;
+      case 1:
+        return 0 - (1 + value);
+      case 2:
+        return this.getBytes(value);
+      case 3:
+        return this.getBytes(value);
+      case 4: {
+        let ret = new Array(value);
+        for (let i = 0; i < value; i++) {
+          ret[i] = this.getCBOR();
+        }
+        return ret;
+      }
+      case 5:
+        if (value == 0) {
+          return {};
+        }
+        let copy = new Cbor(this.data);
+        const [firstKeyMajor] = copy.getCBORHeader();
+        if (firstKeyMajor == 3) {
+          // String-keyed map.
+          let lastKeyHeader = new Cbor(new Uint8Array(0));
+          let lastKeyBytes = new Cbor(new Uint8Array(0));
+          let ret = {};
+          for (let i = 0; i < value; i++) {
+            const [keyMajor, keyLength, keyHeader] = this.getCBORHeader();
+            if (keyMajor != 3) {
+              throw('Cbor: non-string in string-valued map');
+            }
+            const keyBytes = new Cbor(this.getBytes(keyLength));
+            if (i > 0) {
+              const headerCmp = lastKeyHeader.compare(keyHeader);
+              if (headerCmp > 0 ||
+                  (headerCmp == 0 && lastKeyBytes.compare(keyBytes) >= 0)) {
+                throw(
+                    'Cbor: map keys in wrong order: ' + lastKeyHeader.hex +
+                    '/' + lastKeyBytes.hex + ' ' + keyHeader.hex + '/' +
+                    keyBytes.hex);
+              }
+            }
+            lastKeyHeader = keyHeader;
+            lastKeyBytes = keyBytes;
+            ret[keyBytes.parseUTF8()] = this.getCBOR();
+          }
+          return ret;
+        } else if (firstKeyMajor == 0 || firstKeyMajor == 1) {
+          // Number-keyed map.
+          let lastKeyHeader = new Cbor(new Uint8Array(0));
+          let ret = {};
+          for (let i = 0; i < value; i++) {
+            let [keyMajor, keyValue, keyHeader] = this.getCBORHeader();
+            if (keyMajor != 0 && keyMajor != 1) {
+              throw('Cbor: non-number in number-valued map');
+            }
+            if (i > 0 && lastKeyHeader.compare(keyHeader) >= 0) {
+              throw(
+                  'Cbor: map keys in wrong order: ' + lastKeyHeader.hex + ' ' +
+                  keyHeader.hex);
+            }
+            lastKeyHeader = keyHeader;
+            if (keyMajor == 1) {
+              keyValue = 0 - (1 + keyValue);
+            }
+            ret[keyValue] = this.getCBOR();
+          }
+          return ret;
+        } else {
+          throw('Cbor: map keyed by invalid major type ' + firstKeyMajor);
+        }
+      default:
+        throw('Cbor: unhandled major type ' + major);
+    }
+  }
+  parseUTF8() {
+    return (new TextDecoder('utf-8')).decode(this.slice);
+  }
+}
diff --git a/tests/wpt/web-platform-tests/webauthn/webauthn-testdriver-basic.https.html b/tests/wpt/web-platform-tests/webauthn/webauthn-testdriver-basic.https.html
new file mode 100644
index 000000000000..7790f5d0d3fd
--- /dev/null
+++ b/tests/wpt/web-platform-tests/webauthn/webauthn-testdriver-basic.https.html
@@ -0,0 +1,117 @@
+<!DOCTYPE html>
+<title>Successful WebAuthn tests</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/common-inputs.js"></script>
+<script src="resources/utils.js"></script>
+
+<script>
+"use strict";
+
+promise_test(async t => {
+  return window.test_driver.add_virtual_authenticator({
+    protocol: "ctap1/u2f",
+    transport: "usb",
+  });
+}, "Set up the test environment");
+
+let credential;
+let publicKey;
+
+promise_test(async t => {
+  credential = await navigator.credentials.create({
+    publicKey: MAKE_CREDENTIAL_OPTIONS,
+  });
+
+  // Perform the validations the Relying Party should do against the credential.
+  // https://w3c.github.io/webauthn/#sctn-registering-a-new-credential
+  let jsonText =
+    new TextDecoder("utf-8").decode(credential.response.clientDataJSON);
+  let clientData = JSON.parse(jsonText);
+  assert_equals(clientData.type, "webauthn.create");
+  assert_equals(clientData.challenge, base64urlEncode(CHALLENGE));
+  assert_equals(clientData.origin, window.location.origin);
+
+  let attestationObject =
+    new Cbor(credential.response.attestationObject).getCBOR();
+
+  let rpIdHash = new Uint8Array(await crypto.subtle.digest(
+    { name: "SHA-256" }, new TextEncoder("utf-8").encode(PUBLIC_KEY_RP.id)));
+
+  let authenticatorData = parseAuthenticatorData(attestationObject.authData);
+
+  assert_array_equals(authenticatorData.rpIdHash, rpIdHash)
+  assert_true(authenticatorData.flags.up);
+  assert_false(authenticatorData.flags.uv);
+
+  publicKey = authenticatorData.attestedCredentialData.credentialPublicKey;
+  assert_equals(publicKey.alg, PUBLIC_KEY_PARAMETERS[0].alg);
+  assert_equals(publicKey.type, 2 /* EC2 */);
+
+  assert_equals(authenticatorData.extensions, null);
+  assert_object_equals(credential.getClientExtensionResults(), {});
+}, "Create a credential");
+
+promise_test(async t => {
+  let assertion = await navigator.credentials.get({
+    publicKey: {
+      challenge: new TextEncoder("utf-8").encode(CHALLENGE),
+      rpId: PUBLIC_KEY_RP.id,
+      allowCredentials: [{
+        type: "public-key",
+        id: credential.rawId,
+        transports: ["usb"],
+      }],
+      userVerification: "discouraged",
+    },
+  });
+
+  // Perform the validations the Relying Party should do against the assertion.
+  // https://w3c.github.io/webauthn/#sctn-verifying-assertion
+  assert_object_equals(credential.rawId, assertion.rawId);
+  let jsonText =
+    new TextDecoder("utf-8").decode(assertion.response.clientDataJSON);
+  let clientData = JSON.parse(jsonText);
+  assert_equals(clientData.type, "webauthn.get");
+  assert_equals(clientData.challenge, base64urlEncode(CHALLENGE));
+  assert_equals(clientData.type, "webauthn.get");
+  assert_equals(clientData.origin, window.location.origin);
+
+  let binaryAuthenticatorData =
+    new Uint8Array(assertion.response.authenticatorData);
+
+  let authenticatorData = parseAuthenticatorData(binaryAuthenticatorData);
+
+  let rpIdHash = new Uint8Array(await crypto.subtle.digest(
+    { name: "SHA-256" }, new TextEncoder("utf-8").encode(PUBLIC_KEY_RP.id)));
+
+  assert_array_equals(authenticatorData.rpIdHash, rpIdHash)
+  assert_true(authenticatorData.flags.up);
+  assert_false(authenticatorData.flags.uv);
+
+  assert_equals(authenticatorData.extensions, null);
+  assert_object_equals(credential.getClientExtensionResults(), {});
+  assert_equals(authenticatorData.attestedCredentialData, null);
+
+  let jwkPublicKey = coseObjectToJWK(publicKey);
+  let key = await crypto.subtle.importKey(
+    "jwk", jwkPublicKey, {name: "ECDSA", namedCurve: "P-256"},
+    /*extractable=*/false, ["verify"]);
+
+  let signature =
+    convertDERSignatureToSubtle(new Uint8Array(assertion.response.signature));
+
+  let clientDataJsonHash = new Uint8Array(await crypto.subtle.digest(
+    "SHA-256", assertion.response.clientDataJSON));
+  let signedData =
+    new Uint8Array(binaryAuthenticatorData.length + clientDataJsonHash.length);
+  signedData.set(binaryAuthenticatorData);
+  signedData.set(clientDataJsonHash, binaryAuthenticatorData.length);
+
+  assert_true(await crypto.subtle.verify(
+    { name: "ECDSA", hash: "SHA-256" }, key, signature, signedData));
+}, "Get an assertion");
+
+</script>