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 3a3d15b8406..3b874fc1748 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
@@ -14,9 +14,6 @@
   [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]
diff --git a/tests/wpt/metadata/MANIFEST.json b/tests/wpt/metadata/MANIFEST.json
index c5acdb9ee11..a8bdf749ea3 100644
--- a/tests/wpt/metadata/MANIFEST.json
+++ b/tests/wpt/metadata/MANIFEST.json
@@ -294514,6 +294514,11 @@
      {}
     ]
    ],
+   "docs/running-tests/command-line-arguments.md": [
+    [
+     {}
+    ]
+   ],
    "docs/running-tests/custom-runner.md": [
     [
      {}
@@ -344689,26 +344694,344 @@
      {}
     ]
    ],
-   "IndexedDB/nested-cloning-large-multiple.html": [
+   "IndexedDB/nested-cloning-large-multiple.any.js": [
     [
-     "IndexedDB/nested-cloning-large-multiple.html",
+     "IndexedDB/nested-cloning-large-multiple.any.html",
      {
+      "script_metadata": [
+       [
+        "title",
+        "IndexedDB: large nested objects are cloned correctly"
+       ],
+       [
+        "timeout",
+        "long"
+       ],
+       [
+        "script",
+        "support-promises.js"
+       ],
+       [
+        "script",
+        "nested-cloning-common.js"
+       ],
+       [
+        "global",
+        "window,dedicatedworker,sharedworker,serviceworker"
+       ]
+      ],
+      "timeout": "long"
+     }
+    ],
+    [
+     "IndexedDB/nested-cloning-large-multiple.any.serviceworker.html",
+     {
+      "script_metadata": [
+       [
+        "title",
+        "IndexedDB: large nested objects are cloned correctly"
+       ],
+       [
+        "timeout",
+        "long"
+       ],
+       [
+        "script",
+        "support-promises.js"
+       ],
+       [
+        "script",
+        "nested-cloning-common.js"
+       ],
+       [
+        "global",
+        "window,dedicatedworker,sharedworker,serviceworker"
+       ]
+      ],
+      "timeout": "long"
+     }
+    ],
+    [
+     "IndexedDB/nested-cloning-large-multiple.any.sharedworker.html",
+     {
+      "script_metadata": [
+       [
+        "title",
+        "IndexedDB: large nested objects are cloned correctly"
+       ],
+       [
+        "timeout",
+        "long"
+       ],
+       [
+        "script",
+        "support-promises.js"
+       ],
+       [
+        "script",
+        "nested-cloning-common.js"
+       ],
+       [
+        "global",
+        "window,dedicatedworker,sharedworker,serviceworker"
+       ]
+      ],
+      "timeout": "long"
+     }
+    ],
+    [
+     "IndexedDB/nested-cloning-large-multiple.any.worker.html",
+     {
+      "script_metadata": [
+       [
+        "title",
+        "IndexedDB: large nested objects are cloned correctly"
+       ],
+       [
+        "timeout",
+        "long"
+       ],
+       [
+        "script",
+        "support-promises.js"
+       ],
+       [
+        "script",
+        "nested-cloning-common.js"
+       ],
+       [
+        "global",
+        "window,dedicatedworker,sharedworker,serviceworker"
+       ]
+      ],
       "timeout": "long"
      }
     ]
    ],
-   "IndexedDB/nested-cloning-large.html": [
+   "IndexedDB/nested-cloning-large.any.js": [
     [
-     "IndexedDB/nested-cloning-large.html",
+     "IndexedDB/nested-cloning-large.any.html",
      {
+      "script_metadata": [
+       [
+        "title",
+        "IndexedDB: large nested objects are cloned correctly"
+       ],
+       [
+        "timeout",
+        "long"
+       ],
+       [
+        "script",
+        "support-promises.js"
+       ],
+       [
+        "script",
+        "nested-cloning-common.js"
+       ],
+       [
+        "global",
+        "window,dedicatedworker,sharedworker,serviceworker"
+       ]
+      ],
+      "timeout": "long"
+     }
+    ],
+    [
+     "IndexedDB/nested-cloning-large.any.serviceworker.html",
+     {
+      "script_metadata": [
+       [
+        "title",
+        "IndexedDB: large nested objects are cloned correctly"
+       ],
+       [
+        "timeout",
+        "long"
+       ],
+       [
+        "script",
+        "support-promises.js"
+       ],
+       [
+        "script",
+        "nested-cloning-common.js"
+       ],
+       [
+        "global",
+        "window,dedicatedworker,sharedworker,serviceworker"
+       ]
+      ],
+      "timeout": "long"
+     }
+    ],
+    [
+     "IndexedDB/nested-cloning-large.any.sharedworker.html",
+     {
+      "script_metadata": [
+       [
+        "title",
+        "IndexedDB: large nested objects are cloned correctly"
+       ],
+       [
+        "timeout",
+        "long"
+       ],
+       [
+        "script",
+        "support-promises.js"
+       ],
+       [
+        "script",
+        "nested-cloning-common.js"
+       ],
+       [
+        "global",
+        "window,dedicatedworker,sharedworker,serviceworker"
+       ]
+      ],
+      "timeout": "long"
+     }
+    ],
+    [
+     "IndexedDB/nested-cloning-large.any.worker.html",
+     {
+      "script_metadata": [
+       [
+        "title",
+        "IndexedDB: large nested objects are cloned correctly"
+       ],
+       [
+        "timeout",
+        "long"
+       ],
+       [
+        "script",
+        "support-promises.js"
+       ],
+       [
+        "script",
+        "nested-cloning-common.js"
+       ],
+       [
+        "global",
+        "window,dedicatedworker,sharedworker,serviceworker"
+       ]
+      ],
       "timeout": "long"
      }
     ]
    ],
-   "IndexedDB/nested-cloning-small.html": [
+   "IndexedDB/nested-cloning-small.any.js": [
     [
-     "IndexedDB/nested-cloning-small.html",
+     "IndexedDB/nested-cloning-small.any.html",
      {
+      "script_metadata": [
+       [
+        "title",
+        "IndexedDB: small nested objects are cloned correctly"
+       ],
+       [
+        "timeout",
+        "long"
+       ],
+       [
+        "script",
+        "support-promises.js"
+       ],
+       [
+        "script",
+        "nested-cloning-common.js"
+       ],
+       [
+        "global",
+        "window,dedicatedworker,sharedworker,serviceworker"
+       ]
+      ],
+      "timeout": "long"
+     }
+    ],
+    [
+     "IndexedDB/nested-cloning-small.any.serviceworker.html",
+     {
+      "script_metadata": [
+       [
+        "title",
+        "IndexedDB: small nested objects are cloned correctly"
+       ],
+       [
+        "timeout",
+        "long"
+       ],
+       [
+        "script",
+        "support-promises.js"
+       ],
+       [
+        "script",
+        "nested-cloning-common.js"
+       ],
+       [
+        "global",
+        "window,dedicatedworker,sharedworker,serviceworker"
+       ]
+      ],
+      "timeout": "long"
+     }
+    ],
+    [
+     "IndexedDB/nested-cloning-small.any.sharedworker.html",
+     {
+      "script_metadata": [
+       [
+        "title",
+        "IndexedDB: small nested objects are cloned correctly"
+       ],
+       [
+        "timeout",
+        "long"
+       ],
+       [
+        "script",
+        "support-promises.js"
+       ],
+       [
+        "script",
+        "nested-cloning-common.js"
+       ],
+       [
+        "global",
+        "window,dedicatedworker,sharedworker,serviceworker"
+       ]
+      ],
+      "timeout": "long"
+     }
+    ],
+    [
+     "IndexedDB/nested-cloning-small.any.worker.html",
+     {
+      "script_metadata": [
+       [
+        "title",
+        "IndexedDB: small nested objects are cloned correctly"
+       ],
+       [
+        "timeout",
+        "long"
+       ],
+       [
+        "script",
+        "support-promises.js"
+       ],
+       [
+        "script",
+        "nested-cloning-common.js"
+       ],
+       [
+        "global",
+        "window,dedicatedworker,sharedworker,serviceworker"
+       ]
+      ],
       "timeout": "long"
      }
     ]
@@ -488104,16 +488427,16 @@
    "db5f710ceb5652ed8b9746f883948fac41262d6b",
    "support"
   ],
-  "IndexedDB/nested-cloning-large-multiple.html": [
-   "f263efbcf6d8f1601e623690ba0de799edce406b",
+  "IndexedDB/nested-cloning-large-multiple.any.js": [
+   "d64df916d801b106759fb0ca2e6547d5686fac8d",
    "testharness"
   ],
-  "IndexedDB/nested-cloning-large.html": [
-   "6e4f9be2ee6ce57605ad0248f37f794f6d8a70a2",
+  "IndexedDB/nested-cloning-large.any.js": [
+   "cadfeb04599d2c946037a8a726ea37357fb41172",
    "testharness"
   ],
-  "IndexedDB/nested-cloning-small.html": [
-   "558415f2342038eb079b4267fdcb0b133fbb9da8",
+  "IndexedDB/nested-cloning-small.any.js": [
+   "864752827a9afd1932f1e0978e1cff825af42fb4",
    "testharness"
   ],
   "IndexedDB/objectstore_keyorder.htm": [
@@ -642433,11 +642756,11 @@
    "reftest"
   ],
   "css/vendor-imports/mozilla/mozilla-central-reftests/contain/contain-layout-suppress-baseline-002-ref.html": [
-   "d4095fd987b83596f4884b77e87a759d506bda9b",
+   "0587c90c35e20733c9489982c161214be0444cbf",
    "support"
   ],
   "css/vendor-imports/mozilla/mozilla-central-reftests/contain/contain-layout-suppress-baseline-002.html": [
-   "845290768acbe5b3bd81d4c78e4a4cf61fecc906",
+   "a370386edeea604609831bfdf1df7757d370f747",
    "reftest"
   ],
   "css/vendor-imports/mozilla/mozilla-central-reftests/contain/contain-paint-clip-001-ref.html": [
@@ -642717,7 +643040,7 @@
    "reftest"
   ],
   "css/vendor-imports/mozilla/mozilla-central-reftests/contain/reftest.list": [
-   "eaf31a7dc12937847b0d850dadb3ad0ee6cadcc4",
+   "9a70ca1e9ae609f583a9837916718392e799571c",
    "support"
   ],
   "css/vendor-imports/mozilla/mozilla-central-reftests/counter-styles-3/dependent-builtin-ref.html": [
@@ -650957,7 +651280,7 @@
    "support"
   ],
   "docs/conf.py": [
-   "c295c3d9e7fc812fe99b31c29ed4e232713801f0",
+   "b3bce7971129bc2b4f62a86f4798ec69c49d7cc8",
    "support"
   ],
   "docs/index.rst": [
@@ -650973,7 +651296,7 @@
    "support"
   ],
   "docs/requirements.txt": [
-   "d888313b041f49a5c17124bfa18471ff882c1326",
+   "dceaed13bc3f2a724f2ff204ea0824df80977193",
    "support"
   ],
   "docs/reviewing-tests/checklist.md": [
@@ -650996,12 +651319,16 @@
    "5851cd5572264cb06066b9c8d6721bd1fe995a0a",
    "support"
   ],
+  "docs/running-tests/command-line-arguments.md": [
+   "598c9da2a10514062ee3ea06d5c5335677763e32",
+   "support"
+  ],
   "docs/running-tests/custom-runner.md": [
    "4e860edbb21193a82d7333541eb55ada124c82f1",
    "support"
   ],
   "docs/running-tests/from-local-system.md": [
-   "3cc4d9735ff1223d263a5b2bf6f72b9a2fa8c3eb",
+   "695f8403da4a8a52eddb25492ac89edd7c33e6e7",
    "support"
   ],
   "docs/running-tests/from-web.md": [
@@ -719977,7 +720304,7 @@
    "support"
   ],
   "tools/wpt/wpt.py": [
-   "909d435b6485f7e78c996ef02960160b53a0851c",
+   "4130e1eecf8ae52dbc0b68f6cd59010dd4e435e4",
    "support"
   ],
   "tools/wptrunner/.gitignore": [
diff --git a/tests/wpt/metadata/css/cssom-view/matchMedia-display-none-iframe.html.ini b/tests/wpt/metadata/css/cssom-view/matchMedia-display-none-iframe.html.ini
new file mode 100644
index 00000000000..e6e1f29e274
--- /dev/null
+++ b/tests/wpt/metadata/css/cssom-view/matchMedia-display-none-iframe.html.ini
@@ -0,0 +1,2 @@
+[matchMedia-display-none-iframe.html]
+  expected: ERROR
diff --git a/tests/wpt/metadata/fetch/content-type/response.window.js.ini b/tests/wpt/metadata/fetch/content-type/response.window.js.ini
index 8ee00ab8dc0..526971acaba 100644
--- a/tests/wpt/metadata/fetch/content-type/response.window.js.ini
+++ b/tests/wpt/metadata/fetch/content-type/response.window.js.ini
@@ -312,27 +312,24 @@
   [<iframe>: separate response Content-Type: text/plain */*;charset=gbk]
     expected: FAIL
 
-  [<iframe>: combined response Content-Type: text/html;" \\" text/plain]
-    expected: FAIL
-
-  [<iframe>: separate response Content-Type: text/html */*]
-    expected: FAIL
-
-  [<iframe>: combined response Content-Type: text/html;" text/plain]
-    expected: FAIL
-
   [<iframe>: combined response Content-Type: */* text/html]
     expected: FAIL
 
   [<iframe>: combined response Content-Type: text/html;charset=gbk text/plain text/html]
     expected: FAIL
 
-  [<iframe>: combined response Content-Type: text/html */*]
-    expected: FAIL
-
   [<iframe>: combined response Content-Type: text/html */*;charset=gbk]
     expected: FAIL
 
-  [<iframe>: combined response Content-Type: text/html;x=" text/plain]
+  [<iframe>: separate response Content-Type: text/html;charset=gbk text/plain text/html]
+    expected: FAIL
+
+  [<iframe>: separate response Content-Type: */* text/html]
+    expected: FAIL
+
+  [<iframe>: separate response Content-Type: text/html;x=" text/plain]
+    expected: FAIL
+
+  [<iframe>: separate response Content-Type: text/html;" \\" text/plain]
     expected: FAIL
 
diff --git a/tests/wpt/metadata/fetch/nosniff/parsing-nosniff.window.js.ini b/tests/wpt/metadata/fetch/nosniff/parsing-nosniff.window.js.ini
index a639f15230c..849e7ec770e 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 +11,9 @@
   [X-Content-Type-Options%3A%20nosniff%0C]
     expected: FAIL
 
-  [Content-Type-Options%3A%20nosniff]
+  [X-Content-Type-Options%3A%20'NosniFF']
+    expected: FAIL
+
+  [X-Content-Type-Options%3A%20no%0D%0AX-Content-Type-Options%3A%20nosniff]
     expected: FAIL
 
diff --git a/tests/wpt/metadata/html/browsers/history/the-history-interface/traverse_the_history_1.html.ini b/tests/wpt/metadata/html/browsers/history/the-history-interface/traverse_the_history_1.html.ini
new file mode 100644
index 00000000000..87b07c3e670
--- /dev/null
+++ b/tests/wpt/metadata/html/browsers/history/the-history-interface/traverse_the_history_1.html.ini
@@ -0,0 +1,4 @@
+[traverse_the_history_1.html]
+  [Multiple history traversals from the same task]
+    expected: FAIL
+
diff --git a/tests/wpt/metadata/html/browsers/history/the-history-interface/traverse_the_history_2.html.ini b/tests/wpt/metadata/html/browsers/history/the-history-interface/traverse_the_history_2.html.ini
new file mode 100644
index 00000000000..75d75b4cda2
--- /dev/null
+++ b/tests/wpt/metadata/html/browsers/history/the-history-interface/traverse_the_history_2.html.ini
@@ -0,0 +1,4 @@
+[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_4.html.ini b/tests/wpt/metadata/html/browsers/history/the-history-interface/traverse_the_history_4.html.ini
new file mode 100644
index 00000000000..385376c7321
--- /dev/null
+++ b/tests/wpt/metadata/html/browsers/history/the-history-interface/traverse_the_history_4.html.ini
@@ -0,0 +1,4 @@
+[traverse_the_history_4.html]
+  [Multiple history traversals, last would be aborted]
+    expected: FAIL
+
diff --git a/tests/wpt/metadata/html/semantics/embedded-content/the-img-element/non-active-document.html.ini b/tests/wpt/metadata/html/semantics/embedded-content/the-img-element/non-active-document.html.ini
deleted file mode 100644
index 8cc42056d34..00000000000
--- a/tests/wpt/metadata/html/semantics/embedded-content/the-img-element/non-active-document.html.ini
+++ /dev/null
@@ -1,10 +0,0 @@
-[non-active-document.html]
-  [DOMParser]
-    expected: FAIL
-
-  [createHTMLDocument]
-    expected: FAIL
-
-  [<template>]
-    expected: FAIL
-
diff --git a/tests/wpt/metadata/html/semantics/scripting-1/the-script-element/execution-timing/077.html.ini b/tests/wpt/metadata/html/semantics/scripting-1/the-script-element/execution-timing/077.html.ini
new file mode 100644
index 00000000000..bcd2fd0eab8
--- /dev/null
+++ b/tests/wpt/metadata/html/semantics/scripting-1/the-script-element/execution-timing/077.html.ini
@@ -0,0 +1,4 @@
+[077.html]
+  [ adding several types of scripts through the DOM and removing some of them confuses scheduler ]
+    expected: FAIL
+
diff --git a/tests/wpt/web-platform-tests/IndexedDB/nested-cloning-large-multiple.html b/tests/wpt/web-platform-tests/IndexedDB/nested-cloning-large-multiple.any.js
similarity index 76%
rename from tests/wpt/web-platform-tests/IndexedDB/nested-cloning-large-multiple.html
rename to tests/wpt/web-platform-tests/IndexedDB/nested-cloning-large-multiple.any.js
index f263efbcf6d..d64df916d80 100644
--- a/tests/wpt/web-platform-tests/IndexedDB/nested-cloning-large-multiple.html
+++ b/tests/wpt/web-platform-tests/IndexedDB/nested-cloning-large-multiple.any.js
@@ -1,14 +1,9 @@
-<!doctype html>
-<meta charset="utf8">
-<meta name="timeout" content="long">
-<title>IndexedDB: large nested objects are cloned correctly</title>
-<link rel="help" href="https://w3c.github.io/IndexedDB/#abort-transaction">
-<link rel="author" href="pwnall@chromium.org" title="Victor Costan">
-<script src="/resources/testharness.js"></script>
-<script src="/resources/testharnessreport.js"></script>
-<script src="support-promises.js"></script>
-<script src="nested-cloning-common.js"></script>
-<script>
+// META: title=IndexedDB: large nested objects are cloned correctly
+// META: timeout=long
+// META: script=support-promises.js
+// META: script=nested-cloning-common.js
+// META: global=window,dedicatedworker,sharedworker,serviceworker
+'use strict';
 
 cloningTestWithKeyGenerator(
     'multiple requests of objects with blobs and large typed arrays', [
@@ -50,5 +45,3 @@ cloningTestWithKeyGenerator(
     { type: 'blob', size: wrapThreshold, mimeType: 'text/x-blink20', seed: 20 },
   ],
 ]);
-
-</script>
diff --git a/tests/wpt/web-platform-tests/IndexedDB/nested-cloning-large.html b/tests/wpt/web-platform-tests/IndexedDB/nested-cloning-large.any.js
similarity index 71%
rename from tests/wpt/web-platform-tests/IndexedDB/nested-cloning-large.html
rename to tests/wpt/web-platform-tests/IndexedDB/nested-cloning-large.any.js
index 6e4f9be2ee6..cadfeb04599 100644
--- a/tests/wpt/web-platform-tests/IndexedDB/nested-cloning-large.html
+++ b/tests/wpt/web-platform-tests/IndexedDB/nested-cloning-large.any.js
@@ -1,14 +1,9 @@
-<!doctype html>
-<meta charset="utf8">
-<meta name="timeout" content="long">
-<title>IndexedDB: large nested objects are cloned correctly</title>
-<link rel="help" href="https://w3c.github.io/IndexedDB/#abort-transaction">
-<link rel="author" href="pwnall@chromium.org" title="Victor Costan">
-<script src="/resources/testharness.js"></script>
-<script src="/resources/testharnessreport.js"></script>
-<script src="support-promises.js"></script>
-<script src="nested-cloning-common.js"></script>
-<script>
+// META: title=IndexedDB: large nested objects are cloned correctly
+// META: timeout=long
+// META: script=support-promises.js
+// META: script=nested-cloning-common.js
+// META: global=window,dedicatedworker,sharedworker,serviceworker
+'use strict';
 
 cloningTest('large typed array', [
   { type: 'buffer', size: wrapThreshold, seed: 1 },
@@ -45,5 +40,3 @@ cloningTestWithKeyGenerator('object with blobs and large typed arrays', [
              seed: 5 },
   },
 ]);
-
-</script>
diff --git a/tests/wpt/web-platform-tests/IndexedDB/nested-cloning-small.html b/tests/wpt/web-platform-tests/IndexedDB/nested-cloning-small.any.js
similarity index 68%
rename from tests/wpt/web-platform-tests/IndexedDB/nested-cloning-small.html
rename to tests/wpt/web-platform-tests/IndexedDB/nested-cloning-small.any.js
index 558415f2342..864752827a9 100644
--- a/tests/wpt/web-platform-tests/IndexedDB/nested-cloning-small.html
+++ b/tests/wpt/web-platform-tests/IndexedDB/nested-cloning-small.any.js
@@ -1,14 +1,9 @@
-<!doctype html>
-<meta charset="utf8">
-<meta name="timeout" content="long">
-<title>IndexedDB: small nested objects are cloned correctly</title>
-<link rel="help" href="https://w3c.github.io/IndexedDB/#abort-transaction">
-<link rel="author" href="pwnall@chromium.org" title="Victor Costan">
-<script src="/resources/testharness.js"></script>
-<script src="/resources/testharnessreport.js"></script>
-<script src="support-promises.js"></script>
-<script src="nested-cloning-common.js"></script>
-<script>
+// META: title=IndexedDB: small nested objects are cloned correctly
+// META: timeout=long
+// META: script=support-promises.js
+// META: script=nested-cloning-common.js
+// META: global=window,dedicatedworker,sharedworker,serviceworker
+'use strict';
 
 cloningTest('small typed array', [
   { type: 'buffer', size: 64, seed: 1 },
@@ -42,6 +37,4 @@ cloningTestWithKeyGenerator('array of blobs and small typed arrays', [
     { type: 'buffer', size: 64, seed: 4 },
     { type: 'blob', size: wrapThreshold, mimeType: 'text/x-blink-05', seed: 5 },
   ],
-]);
-
-</script>
+]);
\ No newline at end of file
diff --git a/tests/wpt/web-platform-tests/css/vendor-imports/mozilla/mozilla-central-reftests/contain/contain-layout-suppress-baseline-002-ref.html b/tests/wpt/web-platform-tests/css/vendor-imports/mozilla/mozilla-central-reftests/contain/contain-layout-suppress-baseline-002-ref.html
index d4095fd987b..0587c90c35e 100644
--- a/tests/wpt/web-platform-tests/css/vendor-imports/mozilla/mozilla-central-reftests/contain/contain-layout-suppress-baseline-002-ref.html
+++ b/tests/wpt/web-platform-tests/css/vendor-imports/mozilla/mozilla-central-reftests/contain/contain-layout-suppress-baseline-002-ref.html
@@ -8,19 +8,18 @@
   .flexBaselineCheck {
     display: flex;
     border: 1px solid black;
-    height: 70px;
   }
   .flexBaselineCheck > * {
     border: 2px solid teal;
-
     /* In the testcase, the (baseline-aligned) items should all have their
        bottom borders aligned with the 50px-tall canvas.  In other words, their
-       bottom borders should all be 20px away from the bottom of their flex
-       container.  Here in the reference case, we just use "flex-end" alignment
-       plus a hardcoded 20px margin-bottom to produce a precise reference
-       for what that should look like. */
+       bottom borders should all be aligned at the bottom of their flex
+       container, separated from the bottom by only by their margin-end
+       distance.  Here in the reference case, we just use "flex-end" alignment
+       (plus the same amount of margin) to produce a precise reference for what
+       that should look like. */
     align-self: flex-end;
-    margin-bottom: 20px;
+    margin: 2px;
   }
   canvas {
     background: purple;
diff --git a/tests/wpt/web-platform-tests/css/vendor-imports/mozilla/mozilla-central-reftests/contain/contain-layout-suppress-baseline-002.html b/tests/wpt/web-platform-tests/css/vendor-imports/mozilla/mozilla-central-reftests/contain/contain-layout-suppress-baseline-002.html
index 845290768ac..a370386edee 100644
--- a/tests/wpt/web-platform-tests/css/vendor-imports/mozilla/mozilla-central-reftests/contain/contain-layout-suppress-baseline-002.html
+++ b/tests/wpt/web-platform-tests/css/vendor-imports/mozilla/mozilla-central-reftests/contain/contain-layout-suppress-baseline-002.html
@@ -11,12 +11,12 @@
   .flexBaselineCheck {
     display: flex;
     border: 1px solid black;
-    height: 70px;
   }
   .flexBaselineCheck > * {
     contain: layout;
     border: 2px solid teal;
     align-self: baseline;
+    margin: 2px;
   }
   canvas {
     background: purple;
diff --git a/tests/wpt/web-platform-tests/css/vendor-imports/mozilla/mozilla-central-reftests/contain/reftest.list b/tests/wpt/web-platform-tests/css/vendor-imports/mozilla/mozilla-central-reftests/contain/reftest.list
index eaf31a7dc12..9a70ca1e9ae 100644
--- a/tests/wpt/web-platform-tests/css/vendor-imports/mozilla/mozilla-central-reftests/contain/reftest.list
+++ b/tests/wpt/web-platform-tests/css/vendor-imports/mozilla/mozilla-central-reftests/contain/reftest.list
@@ -48,3 +48,10 @@
 == contain-layout-ignored-cases-no-principal-box-003.html contain-layout-ignored-cases-no-principal-box-003-ref.html
 == contain-layout-suppress-baseline-001.html contain-layout-suppress-baseline-001-ref.html
 == contain-layout-suppress-baseline-002.html contain-layout-suppress-baseline-002-ref.html
+
+# The following lines are duplicates of other lines from further up in this
+# manifest. They're listed again here so we can re-run these tests with
+# column-span enabled. These lines can be removed once the pref becomes
+# default-enabled (Bug 1426010).
+== contain-size-multicol-002.html contain-size-multicol-002-ref.html
+== contain-size-multicol-003.html contain-size-multicol-003-ref.html
diff --git a/tests/wpt/web-platform-tests/docs/conf.py b/tests/wpt/web-platform-tests/docs/conf.py
index c295c3d9e7f..b3bce797112 100644
--- a/tests/wpt/web-platform-tests/docs/conf.py
+++ b/tests/wpt/web-platform-tests/docs/conf.py
@@ -12,9 +12,12 @@
 # add these directories to sys.path here. If the directory is relative to the
 # documentation root, use os.path.abspath to make it absolute, like shown here.
 #
-#import os
-#import sys
-#sys.path.insert(0, os.path.abspath('.'))
+import os
+import sys
+sys.path.insert(0, os.path.abspath('..'))
+sys.path.insert(0, os.path.abspath('../tools/wptserve'))
+sys.path.insert(0, os.path.abspath('../tools'))
+import localpaths
 
 # -- Project information -----------------------------------------------------
 
@@ -38,7 +41,8 @@ release = u''
 # extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
 # ones.
 extensions = [
-    'recommonmark'
+    'recommonmark',
+    'sphinxarg.ext'
 ]
 
 # Add any paths that contain templates here, relative to this directory.
diff --git a/tests/wpt/web-platform-tests/docs/requirements.txt b/tests/wpt/web-platform-tests/docs/requirements.txt
index d888313b041..dceaed13bc3 100644
--- a/tests/wpt/web-platform-tests/docs/requirements.txt
+++ b/tests/wpt/web-platform-tests/docs/requirements.txt
@@ -1,2 +1,3 @@
 recommonmark==0.5.0
 Sphinx==1.8.5
+sphinx-argparse==0.2.5
diff --git a/tests/wpt/web-platform-tests/docs/running-tests/command-line-arguments.md b/tests/wpt/web-platform-tests/docs/running-tests/command-line-arguments.md
new file mode 100644
index 00000000000..598c9da2a10
--- /dev/null
+++ b/tests/wpt/web-platform-tests/docs/running-tests/command-line-arguments.md
@@ -0,0 +1,14 @@
+# Command-Line Arguments
+
+The `wpt` command-line application offers a number of features for interacting
+with WPT. The functionality is organized into "sub-commands", and each accepts
+a different set of command-line arguments.
+
+This page documents all of the available sub-commands and associated arguments.
+
+```eval_rst
+.. argparse::
+   :module: tools.wpt.wpt
+   :func: create_complete_parser
+   :prog: wpt
+```
diff --git a/tests/wpt/web-platform-tests/docs/running-tests/from-local-system.md b/tests/wpt/web-platform-tests/docs/running-tests/from-local-system.md
index 3cc4d9735ff..695f8403da4 100644
--- a/tests/wpt/web-platform-tests/docs/running-tests/from-local-system.md
+++ b/tests/wpt/web-platform-tests/docs/running-tests/from-local-system.md
@@ -97,6 +97,9 @@ customising the test run:
 
     ./wpt run --help
 
+[A complete listing of the command-line arguments is available
+here](command-line-arguments).
+
 Additional browser-specific documentation:
 
 ```eval_rst
diff --git a/tests/wpt/web-platform-tests/tools/wpt/wpt.py b/tests/wpt/web-platform-tests/tools/wpt/wpt.py
index 909d435b648..4130e1eecf8 100644
--- a/tests/wpt/web-platform-tests/tools/wpt/wpt.py
+++ b/tests/wpt/web-platform-tests/tools/wpt/wpt.py
@@ -80,6 +80,34 @@ def import_command(prog, command, props):
     return script, parser
 
 
+def create_complete_parser():
+    """Eagerly load all subparsers. This involves more work than is required
+    for typical command-line usage. It is maintained for the purposes of
+    documentation generation as implemented in WPT's top-level `/docs`
+    directory."""
+
+    commands = load_commands()
+    parser = argparse.ArgumentParser()
+    subparsers = parser.add_subparsers()
+
+    for command in commands:
+        props = commands[command]
+
+        if props["virtualenv"]:
+            setup_virtualenv(None, False, props)
+
+        subparser = import_command('wpt', command, props)[1]
+        if not subparser:
+            continue
+
+        subparsers.add_parser(command,
+                              help=props["help"],
+                              add_help=False,
+                              parents=[subparser])
+
+    return parser
+
+
 def setup_virtualenv(path, skip_venv_setup, props):
     if skip_venv_setup and path is None:
         raise ValueError("Must set --venv when --skip-venv-setup is used")