diff --git a/testing/web-platform/meta/MANIFEST.json b/testing/web-platform/meta/MANIFEST.json
index acaecedbe623..349b3b074c07 100644
--- a/testing/web-platform/meta/MANIFEST.json
+++ b/testing/web-platform/meta/MANIFEST.json
@@ -1767,6 +1767,46 @@
         ],
         "url": "/html/rendering/bindings/the-select-element-0/option-label.html"
       },
+      {
+        "path": "html/rendering/bindings/the-textarea-element-0/cols-default.html",
+        "references": [
+          [
+            "/html/rendering/bindings/the-textarea-element-0/textarea-ref.html",
+            "=="
+          ]
+        ],
+        "url": "/html/rendering/bindings/the-textarea-element-0/cols-default.html"
+      },
+      {
+        "path": "html/rendering/bindings/the-textarea-element-0/cols-zero.html",
+        "references": [
+          [
+            "/html/rendering/bindings/the-textarea-element-0/textarea-ref.html",
+            "=="
+          ]
+        ],
+        "url": "/html/rendering/bindings/the-textarea-element-0/cols-zero.html"
+      },
+      {
+        "path": "html/rendering/bindings/the-textarea-element-0/rows-default.html",
+        "references": [
+          [
+            "/html/rendering/bindings/the-textarea-element-0/textarea-ref.html",
+            "=="
+          ]
+        ],
+        "url": "/html/rendering/bindings/the-textarea-element-0/rows-default.html"
+      },
+      {
+        "path": "html/rendering/bindings/the-textarea-element-0/rows-zero.html",
+        "references": [
+          [
+            "/html/rendering/bindings/the-textarea-element-0/textarea-ref.html",
+            "=="
+          ]
+        ],
+        "url": "/html/rendering/bindings/the-textarea-element-0/rows-zero.html"
+      },
       {
         "path": "html/rendering/non-replaced-elements/flow-content-0/figure.html",
         "references": [
@@ -10911,6 +10951,10 @@
         "path": "encoding/api-basics.html",
         "url": "/encoding/api-basics.html"
       },
+      {
+        "path": "encoding/api-invalid-label.html",
+        "url": "/encoding/api-invalid-label.html"
+      },
       {
         "path": "encoding/api-replacement-encodings.html",
         "url": "/encoding/api-replacement-encodings.html"
@@ -21008,6 +21052,54 @@
         "url": "/html/rendering/bindings/the-select-element-0/option-label.html"
       }
     ],
+    "html/rendering/bindings/the-textarea-element-0/cols-default.html": [
+      {
+        "path": "html/rendering/bindings/the-textarea-element-0/cols-default.html",
+        "references": [
+          [
+            "/html/rendering/bindings/the-textarea-element-0/textarea-ref.html",
+            "=="
+          ]
+        ],
+        "url": "/html/rendering/bindings/the-textarea-element-0/cols-default.html"
+      }
+    ],
+    "html/rendering/bindings/the-textarea-element-0/cols-zero.html": [
+      {
+        "path": "html/rendering/bindings/the-textarea-element-0/cols-zero.html",
+        "references": [
+          [
+            "/html/rendering/bindings/the-textarea-element-0/textarea-ref.html",
+            "=="
+          ]
+        ],
+        "url": "/html/rendering/bindings/the-textarea-element-0/cols-zero.html"
+      }
+    ],
+    "html/rendering/bindings/the-textarea-element-0/rows-default.html": [
+      {
+        "path": "html/rendering/bindings/the-textarea-element-0/rows-default.html",
+        "references": [
+          [
+            "/html/rendering/bindings/the-textarea-element-0/textarea-ref.html",
+            "=="
+          ]
+        ],
+        "url": "/html/rendering/bindings/the-textarea-element-0/rows-default.html"
+      }
+    ],
+    "html/rendering/bindings/the-textarea-element-0/rows-zero.html": [
+      {
+        "path": "html/rendering/bindings/the-textarea-element-0/rows-zero.html",
+        "references": [
+          [
+            "/html/rendering/bindings/the-textarea-element-0/textarea-ref.html",
+            "=="
+          ]
+        ],
+        "url": "/html/rendering/bindings/the-textarea-element-0/rows-zero.html"
+      }
+    ],
     "html/rendering/non-replaced-elements/flow-content-0/figure.html": [
       {
         "path": "html/rendering/non-replaced-elements/flow-content-0/figure.html",
@@ -24729,7 +24821,7 @@
       }
     ]
   },
-  "rev": "89b6e2bc460316c7f273712d22f0b2d3a3d0c5be",
+  "rev": "20aef05e164be1ccbbd8f66192f01e778b5e5c18",
   "url_base": "/",
   "version": 2
 }
\ No newline at end of file
diff --git a/testing/web-platform/meta/mozilla-sync b/testing/web-platform/meta/mozilla-sync
index 72a09afb230f..af73402b0de1 100644
--- a/testing/web-platform/meta/mozilla-sync
+++ b/testing/web-platform/meta/mozilla-sync
@@ -1 +1 @@
-ec9e346b36e59c9a4fc6fc1cc5a3687417769191
\ No newline at end of file
+821cd0c3a55889f05c04ed9b6c12c810cd1a6c0f
\ No newline at end of file
diff --git a/testing/web-platform/tests/XMLHttpRequest/send-usp.worker.js b/testing/web-platform/tests/XMLHttpRequest/send-usp.worker.js
index 071b22000470..7fc3d8e041fd 100644
--- a/testing/web-platform/tests/XMLHttpRequest/send-usp.worker.js
+++ b/testing/web-platform/tests/XMLHttpRequest/send-usp.worker.js
@@ -2,3 +2,4 @@ importScripts("/resources/testharness.js");
 importScripts("/resources/testharnessreport.js");
 importScripts("send-usp.js");
 run_test();
+done();
diff --git a/testing/web-platform/tests/encoding/api-invalid-label.html b/testing/web-platform/tests/encoding/api-invalid-label.html
new file mode 100644
index 000000000000..04f939a789d8
--- /dev/null
+++ b/testing/web-platform/tests/encoding/api-invalid-label.html
@@ -0,0 +1,14 @@
+<!DOCTYPE html>
+<title>Encoding API: invalid label</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+
+var invalidLabel = "invalid-invalidLabel"
+
+test(function() {
+    assert_throws(new RangeError(), function() { new TextEncoder(invalidLabel); });
+    assert_throws(new RangeError(), function() { new TextDecoder(invalidLabel); });
+}, 'Invalid label "' + invalidLabel + '" should be rejected by API.');
+
+</script>
diff --git a/testing/web-platform/tests/encoding/api-replacement-encodings.html b/testing/web-platform/tests/encoding/api-replacement-encodings.html
index d0accbc8de81..ef0cdb88ec00 100644
--- a/testing/web-platform/tests/encoding/api-replacement-encodings.html
+++ b/testing/web-platform/tests/encoding/api-replacement-encodings.html
@@ -6,8 +6,8 @@
 <script>
 
 test(function() {
-    assert_throws({name: 'RangeError'}, function() { new TextEncoder('replacement'); });
-    assert_throws({name: 'RangeError'}, function() { new TextDecoder('replacement'); });
+    assert_throws(new RangeError(), function() { new TextEncoder('replacement'); });
+    assert_throws(new RangeError(), function() { new TextDecoder('replacement'); });
 }, 'The "replacement" label should not be a known encoding.');
 
 encodings_table.forEach(function(section) {
@@ -16,8 +16,8 @@ encodings_table.forEach(function(section) {
     }).forEach(function(encoding) {
         encoding.labels.forEach(function(label) {
             test(function() {
-                assert_throws({name: 'RangeError'}, function() { new TextEncoder(label); });
-                assert_throws({name: 'RangeError'}, function() { new TextDecoder(label); });
+                assert_throws(new RangeError(), function() { new TextEncoder(label); });
+                assert_throws(new RangeError(), function() { new TextDecoder(label); });
             }, 'Label for "replacement" should be rejected by API: ' + label);
         });
     });
diff --git a/testing/web-platform/tests/encoding/textencoder-constructor-non-utf.html b/testing/web-platform/tests/encoding/textencoder-constructor-non-utf.html
index f284ad0aa745..82ad56bc46f5 100644
--- a/testing/web-platform/tests/encoding/textencoder-constructor-non-utf.html
+++ b/testing/web-platform/tests/encoding/textencoder-constructor-non-utf.html
@@ -17,7 +17,7 @@ encodings_table.forEach(function(section) {
         } else {
             test(function() {
                 assert_equals(new TextDecoder(encoding.name).encoding, encoding.name);
-                assert_throws({name: 'RangeError'}, function() { new TextEncoder(encoding.name); });
+                assert_throws(new RangeError(), function() { new TextEncoder(encoding.name); });
             }, 'Non-UTF encodings supported only for decode, not encode: ' + encoding.name);
         }
     });
diff --git a/testing/web-platform/tests/html/rendering/bindings/the-textarea-element-0/cols-default.html b/testing/web-platform/tests/html/rendering/bindings/the-textarea-element-0/cols-default.html
new file mode 100644
index 000000000000..067d658dd466
--- /dev/null
+++ b/testing/web-platform/tests/html/rendering/bindings/the-textarea-element-0/cols-default.html
@@ -0,0 +1,5 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>Textarea cols</title>
+<link rel=match href=textarea-ref.html>
+<textarea cols=20></textarea>
diff --git a/testing/web-platform/tests/html/rendering/bindings/the-textarea-element-0/cols-zero.html b/testing/web-platform/tests/html/rendering/bindings/the-textarea-element-0/cols-zero.html
new file mode 100644
index 000000000000..8ecac6bf5a0a
--- /dev/null
+++ b/testing/web-platform/tests/html/rendering/bindings/the-textarea-element-0/cols-zero.html
@@ -0,0 +1,5 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>Textarea cols</title>
+<link rel=match href=textarea-ref.html>
+<textarea cols=0></textarea>
diff --git a/testing/web-platform/tests/html/rendering/bindings/the-textarea-element-0/rows-default.html b/testing/web-platform/tests/html/rendering/bindings/the-textarea-element-0/rows-default.html
new file mode 100644
index 000000000000..5bb9f61eee17
--- /dev/null
+++ b/testing/web-platform/tests/html/rendering/bindings/the-textarea-element-0/rows-default.html
@@ -0,0 +1,5 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>Textarea rows</title>
+<link rel=match href=textarea-ref.html>
+<textarea rows=2></textarea>
diff --git a/testing/web-platform/tests/html/rendering/bindings/the-textarea-element-0/rows-zero.html b/testing/web-platform/tests/html/rendering/bindings/the-textarea-element-0/rows-zero.html
new file mode 100644
index 000000000000..79c8d0ff53b8
--- /dev/null
+++ b/testing/web-platform/tests/html/rendering/bindings/the-textarea-element-0/rows-zero.html
@@ -0,0 +1,5 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>Textarea rows</title>
+<link rel=match href=textarea-ref.html>
+<textarea rows=0></textarea>
diff --git a/testing/web-platform/tests/html/rendering/bindings/the-textarea-element-0/textarea-ref.html b/testing/web-platform/tests/html/rendering/bindings/the-textarea-element-0/textarea-ref.html
new file mode 100644
index 000000000000..f2982808f652
--- /dev/null
+++ b/testing/web-platform/tests/html/rendering/bindings/the-textarea-element-0/textarea-ref.html
@@ -0,0 +1,4 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>Default textarea</title>
+<textarea></textarea>
diff --git a/testing/web-platform/tests/html/semantics/embedded-content/the-img-element/relevant-mutations.html b/testing/web-platform/tests/html/semantics/embedded-content/the-img-element/relevant-mutations.html
index 535bada1f234..2b543812c08c 100644
--- a/testing/web-platform/tests/html/semantics/embedded-content/the-img-element/relevant-mutations.html
+++ b/testing/web-platform/tests/html/semantics/embedded-content/the-img-element/relevant-mutations.html
@@ -107,10 +107,9 @@ function t(desc, func, expect) {
     var img = document.querySelector('[data-desc="' + desc + '"]');
     img.onload = img.onerror = this.unreached_func('update the image data was run');
     if (expect == 'timeout') {
-      setTimeout(this.step_func_done(), 250);
+      setTimeout(this.step_func_done(), 1000);
     } else {
       img['on' + expect] = this.step_func_done(function() {});
-      setTimeout(this.unreached_func('update the image data was not run'), 250)
     }
     func.call(this, img);
   }, desc);
diff --git a/testing/web-platform/tests/html/webappapis/system-state-and-capabilities/the-navigator-object/NavigatorID.js b/testing/web-platform/tests/html/webappapis/system-state-and-capabilities/the-navigator-object/NavigatorID.js
index 508953161913..cf16c68d4416 100644
--- a/testing/web-platform/tests/html/webappapis/system-state-and-capabilities/the-navigator-object/NavigatorID.js
+++ b/testing/web-platform/tests/html/webappapis/system-state-and-capabilities/the-navigator-object/NavigatorID.js
@@ -22,6 +22,23 @@ function run_test() {
     assert_equals(navigator.product, "Gecko");
   }, "product");
 
+  test(function() {
+    // See https://www.w3.org/Bugs/Public/show_bug.cgi?id=22555
+    if ("window" in self) {
+      // If you identify as WebKit, taintEnabled should not exist.
+      if (navigator.userAgent.indexOf("WebKit") != -1) {
+        assert_false("taintEnabled" in navigator);
+      }
+      // Otherwise it should exist and return false.
+      else {
+        assert_false(navigator.taintEnabled());
+      }
+    } else {
+      // taintEnabled should not exist in workers.
+      assert_false("taintEnabled" in navigator);
+    }
+  }, "taintEnabled");
+
   test(function() {
     assert_equals(typeof navigator.userAgent, "string",
                   "navigator.userAgent should be a string");
diff --git a/testing/web-platform/tests/tools/lint/lint.whitelist b/testing/web-platform/tests/lint.whitelist
similarity index 100%
rename from testing/web-platform/tests/tools/lint/lint.whitelist
rename to testing/web-platform/tests/lint.whitelist
diff --git a/testing/web-platform/tests/resources/idlharness.js b/testing/web-platform/tests/resources/idlharness.js
index 884daeae2161..170b5835392d 100644
--- a/testing/web-platform/tests/resources/idlharness.js
+++ b/testing/web-platform/tests/resources/idlharness.js
@@ -553,6 +553,11 @@ function IdlInterface(obj, is_callback) {
 
     /** An array of IdlInterfaceMembers. */
     this.members = obj.members.map(function(m){return new IdlInterfaceMember(m); });
+    if (this.has_extended_attribute("Unforgeable")) {
+        this.members
+            .filter(m => !m["static"] && (m.type == "attribute" || m.type == "operation"))
+            .forEach(m => m.isUnforgeable = true);
+    }
 
     /**
      * The name (as a string) of the type we inherit from, or null if there is
@@ -1003,7 +1008,26 @@ IdlInterface.prototype.test_member_attribute = function(member)
             assert_false(member.name in self[this.name].prototype,
                 "The prototype object must not have a property " +
                 format_value(member.name));
-            do_interface_attribute_asserts(self, member);
+
+            // Try/catch around the get here, since it can legitimately throw.
+            // If it does, we obviously can't check for equality with direct
+            // invocation of the getter.
+            var gotValue;
+            var propVal;
+            try {
+                propVal = self[member.name];
+                gotValue = true;
+            } catch (e) {
+                gotValue = false;
+            }
+            if (gotValue) {
+                var getter = Object.getOwnPropertyDescriptor(self, member.name).get;
+                assert_equals(typeof(getter), "function",
+                              format_value(member.name) + " must have a getter");
+                assert_equals(propVal, getter.call(undefined),
+                              "Gets on a global should not require an explicit this");
+            }
+            this.do_interface_attribute_asserts(self, member);
         } else {
             assert_true(member.name in self[this.name].prototype,
                 "The prototype object must have a property " +
@@ -1017,7 +1041,7 @@ IdlInterface.prototype.test_member_attribute = function(member)
                 assert_equals(self[this.name].prototype[member.name], undefined,
                               "getting property on prototype object must return undefined");
             }
-            do_interface_attribute_asserts(self[this.name].prototype, member);
+            this.do_interface_attribute_asserts(self[this.name].prototype, member);
         }
     }.bind(this), this.name + " interface: attribute " + member.name);
 };
@@ -1055,7 +1079,7 @@ IdlInterface.prototype.test_member_operation = function(member)
         var memberHolderObject;
         if (member["static"]) {
             assert_own_property(self[this.name], member.name,
-                    "interface prototype object missing static operation");
+                    "interface object missing static operation");
             memberHolderObject = self[this.name];
         } else if (this.is_global()) {
             assert_own_property(self, member.name,
@@ -1067,46 +1091,66 @@ IdlInterface.prototype.test_member_operation = function(member)
             memberHolderObject = self[this.name].prototype;
         }
 
-        var desc = Object.getOwnPropertyDescriptor(memberHolderObject, member.name);
-        // "The property has attributes { [[Writable]]: true,
-        // [[Enumerable]]: true, [[Configurable]]: true }."
-        assert_false("get" in desc, "property has getter");
-        assert_false("set" in desc, "property has setter");
-        assert_true(desc.writable, "property is not writable");
-        assert_true(desc.enumerable, "property is not enumerable");
-        assert_true(desc.configurable, "property is not configurable");
-        // "The value of the property is a Function object whose
-        // behavior is as follows . . ."
-        assert_equals(typeof memberHolderObject[member.name], "function",
-                      "property must be a function");
-        // "The value of the Function object’s “length” property is
-        // a Number determined as follows:
-        // ". . .
-        // "Return the length of the shortest argument list of the
-        // entries in S."
-        //
-        // TODO: Doesn't handle overloading or variadic arguments.
-        assert_equals(memberHolderObject[member.name].length,
-            member.arguments.filter(function(arg) {
-                return !arg.optional;
-            }).length,
-            "property has wrong .length");
+        this.do_member_operation_asserts(memberHolderObject, member);
+    }.bind(this), this.name + " interface: operation " + member.name +
+    "(" + member.arguments.map(function(m) { return m.idlType.idlType; }) +
+    ")");
+};
 
-        // Make some suitable arguments
-        var args = member.arguments.map(function(arg) {
-            return create_suitable_object(arg.idlType);
-        });
+//@}
+IdlInterface.prototype.do_member_operation_asserts = function(memberHolderObject, member)
+//@{
+{
+    var operationUnforgeable = member.isUnforgeable;
+    var desc = Object.getOwnPropertyDescriptor(memberHolderObject, member.name);
+    // "The property has attributes { [[Writable]]: B,
+    // [[Enumerable]]: true, [[Configurable]]: B }, where B is false if the
+    // operation is unforgeable on the interface, and true otherwise".
+    assert_false("get" in desc, "property has getter");
+    assert_false("set" in desc, "property has setter");
+    assert_equals(desc.writable, !operationUnforgeable,
+                  "property should be writable if and only if not unforgeable");
+    assert_true(desc.enumerable, "property is not enumerable");
+    assert_equals(desc.configurable, !operationUnforgeable,
+                  "property should be configurable if and only if not unforgeable");
+    // "The value of the property is a Function object whose
+    // behavior is as follows . . ."
+    assert_equals(typeof memberHolderObject[member.name], "function",
+                  "property must be a function");
+    // "The value of the Function object’s “length” property is
+    // a Number determined as follows:
+    // ". . .
+    // "Return the length of the shortest argument list of the
+    // entries in S."
+    //
+    // TODO: Doesn't handle overloading or variadic arguments.
+    assert_equals(memberHolderObject[member.name].length,
+        member.arguments.filter(function(arg) {
+            return !arg.optional;
+        }).length,
+        "property has wrong .length");
 
-        // "Let O be a value determined as follows:
-        // ". . .
-        // "Otherwise, throw a TypeError."
-        // This should be hit if the operation is not static, there is
-        // no [ImplicitThis] attribute, and the this value is null.
-        //
-        // TODO: We currently ignore the [ImplicitThis] case.
-        if (!member["static"]) {
+    // Make some suitable arguments
+    var args = member.arguments.map(function(arg) {
+        return create_suitable_object(arg.idlType);
+    });
+
+    // "Let O be a value determined as follows:
+    // ". . .
+    // "Otherwise, throw a TypeError."
+    // This should be hit if the operation is not static, there is
+    // no [ImplicitThis] attribute, and the this value is null.
+    //
+    // TODO: We currently ignore the [ImplicitThis] case.  Except we manually
+    // check for globals, since otherwise we'll invoke window.close().  And we
+    // have to skip this test for anything that on the proto chain of "self",
+    // since that does in fact have implicit-this behavior.
+    if (!member["static"]) {
+        if (!this.is_global() &&
+            memberHolderObject[member.name] != self[member.name])
+        {
             assert_throws(new TypeError(), function() {
-                self[this.name].prototype[member.name].apply(null, args);
+                memberHolderObject[member.name].apply(null, args);
             }, "calling operation with this = null didn't throw TypeError");
         }
 
@@ -1116,12 +1160,10 @@ IdlInterface.prototype.test_member_operation = function(member)
         // TODO: Test a platform object that implements some other
         // interface.  (Have to be sure to get inheritance right.)
         assert_throws(new TypeError(), function() {
-            self[this.name].prototype[member.name].apply({}, args);
+            memberHolderObject[member.name].apply({}, args);
         }, "calling operation with this = {} didn't throw TypeError");
-    }.bind(this), this.name + " interface: operation " + member.name +
-    "(" + member.arguments.map(function(m) { return m.idlType.idlType; }) +
-    ")");
-};
+    }
+}
 
 //@}
 IdlInterface.prototype.test_member_stringifier = function(member)
@@ -1150,15 +1192,18 @@ IdlInterface.prototype.test_member_stringifier = function(member)
         assert_own_property(self[this.name].prototype, "toString",
                 "interface prototype object missing non-static operation");
 
+        var stringifierUnforgeable = member.isUnforgeable;
         var desc = Object.getOwnPropertyDescriptor(interfacePrototypeObject, "toString");
         // "The property has attributes { [[Writable]]: B,
         // [[Enumerable]]: true, [[Configurable]]: B }, where B is false if the
         // stringifier is unforgeable on the interface, and true otherwise."
         assert_false("get" in desc, "property has getter");
         assert_false("set" in desc, "property has setter");
-        assert_true(desc.writable, "property is not writable");
+        assert_equals(desc.writable, !stringifierUnforgeable,
+                      "property should be writable if and only if not unforgeable");
         assert_true(desc.enumerable, "property is not enumerable");
-        assert_true(desc.configurable, "property is not configurable");
+        assert_equals(desc.configurable, !stringifierUnforgeable,
+                      "property should be configurable if and only if not unforgeable");
         // "The value of the property is a Function object, which behaves as
         // follows . . ."
         assert_equals(typeof interfacePrototypeObject.toString, "function",
@@ -1203,7 +1248,8 @@ IdlInterface.prototype.test_members = function()
         case "attribute":
             // For unforgeable attributes, we do the checks in
             // test_interface_of instead.
-            if (!member.has_extended_attribute("Unforgeable")) {
+            if (!member.isUnforgeable)
+            {
                 this.test_member_attribute(member);
             }
             break;
@@ -1211,8 +1257,13 @@ IdlInterface.prototype.test_members = function()
         case "operation":
             // TODO: Need to correctly handle multiple operations with the same
             // identifier.
+            // For unforgeable operations, we do the checks in
+            // test_interface_of instead.
             if (member.name) {
-                this.test_member_operation(member);
+                if (!member.isUnforgeable)
+                {
+                    this.test_member_operation(member);
+                }
             } else if (member.stringifier) {
                 this.test_member_stringifier(member);
             }
@@ -1321,13 +1372,26 @@ IdlInterface.prototype.test_interface_of = function(desc, obj, exception, expect
     for (var i = 0; i < this.members.length; i++)
     {
         var member = this.members[i];
-        if (member.has_extended_attribute("Unforgeable"))
+        if (member.type == "attribute" && member.isUnforgeable)
         {
             test(function()
             {
                 assert_equals(exception, null, "Unexpected exception when evaluating object");
                 assert_equals(typeof obj, expected_typeof, "wrong typeof object");
-                do_interface_attribute_asserts(obj, member);
+                this.do_interface_attribute_asserts(obj, member);
+            }.bind(this), this.name + " interface: " + desc + ' must have own property "' + member.name + '"');
+        }
+        else if (member.type == "operation" &&
+                 member.name &&
+                 member.isUnforgeable)
+        {
+            test(function()
+            {
+                assert_equals(exception, null, "Unexpected exception when evaluating object");
+                assert_equals(typeof obj, expected_typeof, "wrong typeof object");
+                assert_own_property(obj, member.name,
+                                    "Doesn't have the unforgeable operation property");
+                this.do_member_operation_asserts(obj, member);
             }.bind(this), this.name + " interface: " + desc + ' must have own property "' + member.name + '"');
         }
         else if ((member.type == "const"
@@ -1340,7 +1404,12 @@ IdlInterface.prototype.test_interface_of = function(desc, obj, exception, expect
                 assert_equals(exception, null, "Unexpected exception when evaluating object");
                 assert_equals(typeof obj, expected_typeof, "wrong typeof object");
                 if (!member["static"]) {
-                    assert_inherits(obj, member.name);
+                    if (!this.is_global()) {
+                        assert_inherits(obj, member.name);
+                    } else {
+                        assert_own_property(obj, member.name);
+                    }
+
                     if (member.type == "const")
                     {
                         assert_equals(obj[member.name], constValue(member.value));
@@ -1381,7 +1450,11 @@ IdlInterface.prototype.test_interface_of = function(desc, obj, exception, expect
                 assert_equals(exception, null, "Unexpected exception when evaluating object");
                 assert_equals(typeof obj, expected_typeof, "wrong typeof object");
                 if (!member["static"]) {
-                    assert_inherits(obj, member.name);
+                    if (!this.is_global() && !member.isUnforgeable) {
+                        assert_inherits(obj, member.name);
+                    } else {
+                        assert_own_property(obj, member.name);
+                    }
                 }
                 else
                 {
@@ -1423,7 +1496,7 @@ IdlInterface.prototype.has_stringifier = function()
 };
 
 //@}
-function do_interface_attribute_asserts(obj, member)
+IdlInterface.prototype.do_interface_attribute_asserts = function(obj, member)
 //@{
 {
     // This function tests WebIDL as of 2015-01-27.
@@ -1451,7 +1524,7 @@ function do_interface_attribute_asserts(obj, member)
     assert_false("value" in desc, 'property descriptor has value but is supposed to be accessor');
     assert_false("writable" in desc, 'property descriptor has "writable" field but is supposed to be accessor');
     assert_true(desc.enumerable, "property is not enumerable");
-    if (member.has_extended_attribute("Unforgeable"))
+    if (member.isUnforgeable)
     {
         assert_false(desc.configurable, "[Unforgeable] property must not be configurable");
     }
@@ -1545,6 +1618,8 @@ function IdlInterfaceMember(obj)
     {
         this.extAttrs = [];
     }
+
+    this.isUnforgeable = this.has_extended_attribute("Unforgeable");
 }
 
 //@}
diff --git a/testing/web-platform/tests/resources/testharness.js b/testing/web-platform/tests/resources/testharness.js
index 748010306c1a..67b0f406c08f 100644
--- a/testing/web-platform/tests/resources/testharness.js
+++ b/testing/web-platform/tests/resources/testharness.js
@@ -71,13 +71,22 @@ policies and contribution forms [3].
 
     WindowTestEnvironment.prototype._dispatch = function(selector, callback_args, message_arg) {
         this._forEach_windows(
-                function(w, is_same_origin) {
-                    if (is_same_origin && selector in w) {
+                function(w, same_origin) {
+                    if (same_origin) {
                         try {
-                            w[selector].apply(undefined, callback_args);
-                        } catch (e) {
-                            if (debug) {
-                                throw e;
+                            var has_selector = selector in w;
+                        } catch(e) {
+                            // If document.domain was set at some point same_origin can be
+                            // wrong and the above will fail.
+                            has_selector = false;
+                        }
+                        if (has_selector) {
+                            try {
+                                w[selector].apply(undefined, callback_args);
+                            } catch (e) {
+                                if (debug) {
+                                    throw e;
+                                }
                             }
                         }
                     }
@@ -1504,7 +1513,7 @@ policies and contribution forms [3].
             status: {
                 status: tests.status.ERROR,
                 message: "Error in worker" + filename + ": " + message,
-                stack: e.stack
+                stack: error.stack
             }
         });
         error.preventDefault();
diff --git a/testing/web-platform/tests/tools/lint/lint.py b/testing/web-platform/tests/tools/lint/lint.py
index e33cc6ef03a6..2d63f01d4038 100644
--- a/testing/web-platform/tests/tools/lint/lint.py
+++ b/testing/web-platform/tests/tools/lint/lint.py
@@ -76,7 +76,7 @@ def whitelist_errors(path, errors):
     global _whitelist_fn
 
     if _whitelist_fn is None:
-        _whitelist_fn = parse_whitelist_file(os.path.join(here, "lint.whitelist"))
+        _whitelist_fn = parse_whitelist_file(os.path.join(repo_root, "lint.whitelist"))
     return _whitelist_fn(path, errors)
 
 class Regexp(object):
diff --git a/testing/web-platform/tests/websockets/interfaces/WebSocket/close/close-basic.html b/testing/web-platform/tests/websockets/interfaces/WebSocket/close/close-basic.html
index 775c83eff536..d031bfbf3e08 100644
--- a/testing/web-platform/tests/websockets/interfaces/WebSocket/close/close-basic.html
+++ b/testing/web-platform/tests/websockets/interfaces/WebSocket/close/close-basic.html
@@ -14,6 +14,8 @@ async_test(function(t) {
     assert_equals(e.wasClean, false, 'e.wasClean = true');
     delete e.wasClean;
     assert_equals(e.wasClean, false, 'delete e.wasClean');
+    delete CloseEvent.prototype.wasClean;
+    assert_equals(e.wasClean, undefined, 'delete CloseEvent.prototype.wasClean');
     t.done();
   });
   ws.close();
diff --git a/testing/web-platform/tests/websockets/interfaces/WebSocket/readyState/003.html b/testing/web-platform/tests/websockets/interfaces/WebSocket/readyState/003.html
index 8071d220e3a4..5ed73191e961 100644
--- a/testing/web-platform/tests/websockets/interfaces/WebSocket/readyState/003.html
+++ b/testing/web-platform/tests/websockets/interfaces/WebSocket/readyState/003.html
@@ -6,10 +6,11 @@
 <div id=log></div>
 <script>
 test(function(t) {
-  delete WebSocket.prototype.readyState;
   var ws = new WebSocket(SCHEME_DOMAIN_PORT+'/');
   ws.close();
   delete ws.readyState;
-  assert_equals(ws.readyState, ws.CLOSING);
+  assert_equals(ws.readyState, ws.CLOSING, 'delete ws.readyState');
+  delete WebSocket.prototype.readyState;
+  assert_equals(ws.readyState, undefined, 'delete WebSocket.prototype.readyState');
 });
 </script>
diff --git a/testing/web-platform/tests/websockets/interfaces/WebSocket/url/003.html b/testing/web-platform/tests/websockets/interfaces/WebSocket/url/003.html
index 12118937123b..3f0a2a289403 100644
--- a/testing/web-platform/tests/websockets/interfaces/WebSocket/url/003.html
+++ b/testing/web-platform/tests/websockets/interfaces/WebSocket/url/003.html
@@ -8,6 +8,8 @@
 test(function() {
   var ws = new WebSocket(SCHEME_DOMAIN_PORT+'/');
   delete ws.url;
-  assert_equals(ws.url, SCHEME_DOMAIN_PORT+'/');
+  assert_equals(ws.url, SCHEME_DOMAIN_PORT+'/', 'delete ws.url');
+  delete WebSocket.prototype.url;
+  assert_equals(ws.url, undefined, 'delete WebSocket.prototype.url');
 });
 </script>
diff --git a/testing/web-platform/tests/workers/interfaces/DedicatedWorkerGlobalScope/EventTarget.worker.js b/testing/web-platform/tests/workers/interfaces/DedicatedWorkerGlobalScope/EventTarget.worker.js
index 190452737938..954c46c07eca 100644
--- a/testing/web-platform/tests/workers/interfaces/DedicatedWorkerGlobalScope/EventTarget.worker.js
+++ b/testing/web-platform/tests/workers/interfaces/DedicatedWorkerGlobalScope/EventTarget.worker.js
@@ -1,9 +1,9 @@
 importScripts("/resources/testharness.js");
 
-test(function() {
+test(function(t) {
     var i = 0;
     addEventListener("message", function listener(evt) {
-        this.step(function() {
+        t.step(function() {
             ++i;
             removeEventListener("message", listener, true);
         });
diff --git a/testing/web-platform/tests/workers/interfaces/WorkerGlobalScope/onerror/exception-in-onerror.html b/testing/web-platform/tests/workers/interfaces/WorkerGlobalScope/onerror/exception-in-onerror.html
index 79adef16014b..4b5af71d516b 100644
--- a/testing/web-platform/tests/workers/interfaces/WorkerGlobalScope/onerror/exception-in-onerror.html
+++ b/testing/web-platform/tests/workers/interfaces/WorkerGlobalScope/onerror/exception-in-onerror.html
@@ -21,7 +21,7 @@ async_test(function() {
     assert_equals(typeof e.message, 'string', 'typeof e.message');
     assert_equals(e.filename, document.URL+'#', 'e.filename');
     assert_equals(typeof e.lineno, 'number', 'typeof e.lineno');
-    assert_equals(typeof e.column, 'number', 'typeof e.column');
+    assert_equals(typeof e.colno, 'number', 'typeof e.column');
     e.preventDefault(); // "handled"
     this.done();
   });
@@ -29,4 +29,4 @@ async_test(function() {
 </script>
 <!--
 */
-//-->
\ No newline at end of file
+//-->
diff --git a/testing/web-platform/tests/workers/interfaces/WorkerGlobalScope/onerror/not-handled.html b/testing/web-platform/tests/workers/interfaces/WorkerGlobalScope/onerror/not-handled.html
index 96ee06dd207b..f6107ada433f 100644
--- a/testing/web-platform/tests/workers/interfaces/WorkerGlobalScope/onerror/not-handled.html
+++ b/testing/web-platform/tests/workers/interfaces/WorkerGlobalScope/onerror/not-handled.html
@@ -21,7 +21,7 @@ async_test(function() {
     assert_equals(typeof e.message, 'string', 'typeof e.message');
     assert_equals(e.filename, document.URL+'#', 'e.filename');
     assert_equals(typeof e.lineno, 'number', 'typeof e.lineno');
-    assert_equals(typeof e.column, 'number', 'typeof e.column');
+    assert_equals(typeof e.colno, 'number', 'typeof e.column');
     e.preventDefault(); // "handled"
     this.done();
   });
@@ -29,4 +29,4 @@ async_test(function() {
 </script>
 <!--
 */
-//-->
\ No newline at end of file
+//-->
diff --git a/testing/web-platform/tests/workers/interfaces/WorkerGlobalScope/onerror/propagate-to-window-onerror.html b/testing/web-platform/tests/workers/interfaces/WorkerGlobalScope/onerror/propagate-to-window-onerror.html
index 006321675b6a..b6a61e2355c0 100644
--- a/testing/web-platform/tests/workers/interfaces/WorkerGlobalScope/onerror/propagate-to-window-onerror.html
+++ b/testing/web-platform/tests/workers/interfaces/WorkerGlobalScope/onerror/propagate-to-window-onerror.html
@@ -16,15 +16,11 @@ setup({
 });
 async_test(function() {
   var worker = new Worker('#');
-  var timeout = setTimeout(this.step_func(function() {
-    assert_unreached();
-  }, 500));
   window.onerror = this.step_func(function(a, b, c, d) {
-    assert_true(typeof a, 'string', 'first argument');
+    assert_equals(typeof a, 'string', 'first argument');
     assert_equals(b, document.URL+'#', 'second argument');
     assert_equals(typeof c, 'number', 'third argument');
     assert_equals(typeof d, 'number', 'fourth argument');
-    clearTimeout(timeout);
     this.done();
     return true; // "handled"
   });