From 59cf735f856154e14cd427a93b25a0d7e86c563c Mon Sep 17 00:00:00 2001
From: Ms2ger <Ms2ger@gmail.com>
Date: Thu, 8 Sep 2016 10:10:37 +0200
Subject: [PATCH 1/3] Allow uncaught exceptions in worker runtime error tests.

---
 .../workers/WorkerGlobalScope_ErrorEvent_colno.htm            | 4 ++++
 .../workers/WorkerGlobalScope_ErrorEvent_filename.htm         | 4 ++++
 .../workers/WorkerGlobalScope_ErrorEvent_lineno.htm           | 4 ++++
 .../workers/WorkerGlobalScope_ErrorEvent_message.htm          | 4 ++++
 .../workers/Worker_ErrorEvent_bubbles_cancelable.htm          | 3 +++
 .../web-platform-tests/workers/Worker_ErrorEvent_filename.htm | 4 ++++
 .../web-platform-tests/workers/Worker_ErrorEvent_lineno.htm   | 4 ++++
 .../web-platform-tests/workers/Worker_ErrorEvent_message.htm  | 4 ++++
 .../wpt/web-platform-tests/workers/Worker_ErrorEvent_type.htm | 4 ++++
 9 files changed, 35 insertions(+)

diff --git a/tests/wpt/web-platform-tests/workers/WorkerGlobalScope_ErrorEvent_colno.htm b/tests/wpt/web-platform-tests/workers/WorkerGlobalScope_ErrorEvent_colno.htm
index b762beeb406..793d6c1807b 100644
--- a/tests/wpt/web-platform-tests/workers/WorkerGlobalScope_ErrorEvent_colno.htm
+++ b/tests/wpt/web-platform-tests/workers/WorkerGlobalScope_ErrorEvent_colno.htm
@@ -4,6 +4,10 @@
 <script src="/resources/testharnessreport.js"></script>
 <div id=log></div>
 <script>
+// The worker events races with the window's load event; if the worker events
+// arrive first, the harness will detect the error event and fail the test.
+setup({ allow_uncaught_exception: true });
+
 async_test(function(t) {
   var worker = new Worker('./support/ErrorEvent.js');
   worker.onmessage = t.step_func_done(function(e) {
diff --git a/tests/wpt/web-platform-tests/workers/WorkerGlobalScope_ErrorEvent_filename.htm b/tests/wpt/web-platform-tests/workers/WorkerGlobalScope_ErrorEvent_filename.htm
index 9390b7441a3..e165a23f418 100644
--- a/tests/wpt/web-platform-tests/workers/WorkerGlobalScope_ErrorEvent_filename.htm
+++ b/tests/wpt/web-platform-tests/workers/WorkerGlobalScope_ErrorEvent_filename.htm
@@ -4,6 +4,10 @@
 <script src="/resources/testharnessreport.js"></script>
 <div id=log></div>
 <script>
+// The worker events races with the window's load event; if the worker events
+// arrive first, the harness will detect the error event and fail the test.
+setup({ allow_uncaught_exception: true });
+
 async_test(function(t) {
   var worker = new Worker('./support/ErrorEvent.js');
   worker.onmessage = t.step_func_done(function(e) {
diff --git a/tests/wpt/web-platform-tests/workers/WorkerGlobalScope_ErrorEvent_lineno.htm b/tests/wpt/web-platform-tests/workers/WorkerGlobalScope_ErrorEvent_lineno.htm
index c3c145d4bb1..dfbc51467da 100644
--- a/tests/wpt/web-platform-tests/workers/WorkerGlobalScope_ErrorEvent_lineno.htm
+++ b/tests/wpt/web-platform-tests/workers/WorkerGlobalScope_ErrorEvent_lineno.htm
@@ -4,6 +4,10 @@
 <script src="/resources/testharnessreport.js"></script>
 <div id=log></div>
 <script>
+// The worker events races with the window's load event; if the worker events
+// arrive first, the harness will detect the error event and fail the test.
+setup({ allow_uncaught_exception: true });
+
 async_test(function(t) {
   var worker = new Worker('./support/ErrorEvent.js');
   worker.onmessage = t.step_func_done(function(e) {
diff --git a/tests/wpt/web-platform-tests/workers/WorkerGlobalScope_ErrorEvent_message.htm b/tests/wpt/web-platform-tests/workers/WorkerGlobalScope_ErrorEvent_message.htm
index 55a7b7fbba2..bc1d2c45b42 100644
--- a/tests/wpt/web-platform-tests/workers/WorkerGlobalScope_ErrorEvent_message.htm
+++ b/tests/wpt/web-platform-tests/workers/WorkerGlobalScope_ErrorEvent_message.htm
@@ -4,6 +4,10 @@
 <script src="/resources/testharnessreport.js"></script>
 <div id=log></div>
 <script>
+// The worker events races with the window's load event; if the worker events
+// arrive first, the harness will detect the error event and fail the test.
+setup({ allow_uncaught_exception: true });
+
 async_test(function(t) {
   var message = 'Error Message';
   var worker = new Worker('./support/ErrorEvent.js');
diff --git a/tests/wpt/web-platform-tests/workers/Worker_ErrorEvent_bubbles_cancelable.htm b/tests/wpt/web-platform-tests/workers/Worker_ErrorEvent_bubbles_cancelable.htm
index 7acff1f5587..4619ee7b531 100644
--- a/tests/wpt/web-platform-tests/workers/Worker_ErrorEvent_bubbles_cancelable.htm
+++ b/tests/wpt/web-platform-tests/workers/Worker_ErrorEvent_bubbles_cancelable.htm
@@ -6,6 +6,9 @@
 <script src="/resources/testharnessreport.js"></script>
 <div id="log"></div>
 <script>
+// The worker events races with the window's load event; if the worker events
+// arrive first, the harness will detect the error event and fail the test.
+setup({ allow_uncaught_exception: true });
 
 async_test(function(t) {
   var worker = new Worker('./support/ErrorEvent.js');
diff --git a/tests/wpt/web-platform-tests/workers/Worker_ErrorEvent_filename.htm b/tests/wpt/web-platform-tests/workers/Worker_ErrorEvent_filename.htm
index 23dda66e6da..0faef6fea2a 100644
--- a/tests/wpt/web-platform-tests/workers/Worker_ErrorEvent_filename.htm
+++ b/tests/wpt/web-platform-tests/workers/Worker_ErrorEvent_filename.htm
@@ -4,6 +4,10 @@
 <script src="/resources/testharnessreport.js"></script>
 <div id=log></div>
 <script>
+// The worker events races with the window's load event; if the worker events
+// arrive first, the harness will detect the error event and fail the test.
+setup({ allow_uncaught_exception: true });
+
 async_test(function(t) {
   var worker = new Worker('./support/ErrorEvent.js');
   worker.onerror = t.step_func_done(function(e) {
diff --git a/tests/wpt/web-platform-tests/workers/Worker_ErrorEvent_lineno.htm b/tests/wpt/web-platform-tests/workers/Worker_ErrorEvent_lineno.htm
index 912cf6e5a28..ad98172960f 100644
--- a/tests/wpt/web-platform-tests/workers/Worker_ErrorEvent_lineno.htm
+++ b/tests/wpt/web-platform-tests/workers/Worker_ErrorEvent_lineno.htm
@@ -4,6 +4,10 @@
 <script src="/resources/testharnessreport.js"></script>
 <div id=log></div>
 <script>
+// The worker events races with the window's load event; if the worker events
+// arrive first, the harness will detect the error event and fail the test.
+setup({ allow_uncaught_exception: true });
+
 async_test(function(t) {
   var worker = new Worker('./support/ErrorEvent.js');
   worker.onerror = t.step_func_done(function(e) {
diff --git a/tests/wpt/web-platform-tests/workers/Worker_ErrorEvent_message.htm b/tests/wpt/web-platform-tests/workers/Worker_ErrorEvent_message.htm
index 10a140c8651..5602d9bc02d 100644
--- a/tests/wpt/web-platform-tests/workers/Worker_ErrorEvent_message.htm
+++ b/tests/wpt/web-platform-tests/workers/Worker_ErrorEvent_message.htm
@@ -4,6 +4,10 @@
 <script src="/resources/testharnessreport.js"></script>
 <div id=log></div>
 <script>
+// The worker events races with the window's load event; if the worker events
+// arrive first, the harness will detect the error event and fail the test.
+setup({ allow_uncaught_exception: true });
+
 async_test(function(t) {
   var message = 'Error Message';
   var worker = new Worker('./support/ErrorEvent.js');
diff --git a/tests/wpt/web-platform-tests/workers/Worker_ErrorEvent_type.htm b/tests/wpt/web-platform-tests/workers/Worker_ErrorEvent_type.htm
index 29fdfdc708a..3a0f85ad9b6 100644
--- a/tests/wpt/web-platform-tests/workers/Worker_ErrorEvent_type.htm
+++ b/tests/wpt/web-platform-tests/workers/Worker_ErrorEvent_type.htm
@@ -4,6 +4,10 @@
 <script src="/resources/testharnessreport.js"></script>
 <div id=log></div>
 <script>
+// The worker events races with the window's load event; if the worker events
+// arrive first, the harness will detect the error event and fail the test.
+setup({ allow_uncaught_exception: true });
+
 async_test(function(t) {
   var worker = new Worker('./support/ErrorEvent.js');
   worker.onerror = t.step_func_done(function(e) {

From 60142f87e27c84e06380e78b683ad4da2ab80f4f Mon Sep 17 00:00:00 2001
From: Ms2ger <Ms2ger@gmail.com>
Date: Mon, 5 Sep 2016 18:02:14 +0200
Subject: [PATCH 2/3] Implement error reporting for workers.

Fixes #3311.
Fixes #13158.
---
 components/script/dom/bindings/global.rs      |  2 +-
 .../script/dom/dedicatedworkerglobalscope.rs  | 46 +++++++++++++++++-
 .../dom/webidls/WorkerGlobalScope.webidl      |  2 +-
 components/script/dom/worker.rs               | 47 ++++++++++++++++++-
 components/script/dom/workerglobalscope.rs    | 13 ++++-
 .../WebCryptoAPI/digest/digest.worker.js.ini  |  2 +-
 .../encrypt_decrypt/aes_cbc.worker.js.ini     |  2 +-
 .../encrypt_decrypt/aes_ctr.worker.js.ini     |  2 +-
 .../encrypt_decrypt/aes_gcm.worker.js.ini     |  2 +-
 .../encrypt_decrypt/rsa.worker.js.ini         |  2 +-
 .../generateKey/failures.worker.js.ini        |  2 +-
 .../failures_AES-CBC.worker.js.ini            |  2 +-
 .../failures_AES-CTR.worker.js.ini            |  2 +-
 .../failures_AES-GCM.worker.js.ini            |  2 +-
 .../generateKey/failures_AES-KW.worker.js.ini |  2 +-
 .../generateKey/failures_ECDH.worker.js.ini   |  2 +-
 .../generateKey/failures_ECDSA.worker.js.ini  |  2 +-
 .../generateKey/failures_HMAC.worker.js.ini   |  2 +-
 .../failures_RSA-OAEP.worker.js.ini           |  2 +-
 .../failures_RSA-PSS.worker.js.ini            |  2 +-
 .../failures_RSASSA-PKCS1-v1_5.worker.js.ini  |  2 +-
 .../generateKey/successes.worker.js.ini       |  2 +-
 .../successes_AES-CBC.worker.js.ini           |  2 +-
 .../successes_AES-CTR.worker.js.ini           |  2 +-
 .../successes_AES-GCM.worker.js.ini           |  2 +-
 .../successes_AES-KW.worker.js.ini            |  2 +-
 .../generateKey/successes_ECDH.worker.js.ini  |  2 +-
 .../generateKey/successes_ECDSA.worker.js.ini |  2 +-
 .../generateKey/successes_HMAC.worker.js.ini  |  2 +-
 .../successes_RSA-OAEP.worker.js.ini          |  2 +-
 .../successes_RSA-PSS.worker.js.ini           |  2 +-
 .../successes_RSASSA-PKCS1-v1_5.worker.js.ini |  2 +-
 ...WorkerGlobalScope_ErrorEvent_colno.htm.ini |  6 ---
 ...kerGlobalScope_ErrorEvent_filename.htm.ini |  6 ---
 ...orkerGlobalScope_ErrorEvent_lineno.htm.ini |  6 ---
 ...rkerGlobalScope_ErrorEvent_message.htm.ini |  6 ---
 ...rker_ErrorEvent_bubbles_cancelable.htm.ini |  6 ---
 .../Worker_ErrorEvent_filename.htm.ini        |  6 ---
 .../workers/Worker_ErrorEvent_lineno.htm.ini  |  6 ---
 .../workers/Worker_ErrorEvent_message.htm.ini |  6 ---
 .../workers/Worker_ErrorEvent_type.htm.ini    |  6 ---
 .../baseurl/alpha/sharedworker.html.ini       |  3 +-
 .../Worker/AbstractWorker.onerror.html.ini    |  6 ---
 .../metadata/workers/interfaces.worker.js.ini |  3 --
 .../onerror/exception-in-onerror.html.ini     |  6 ---
 .../onerror/handled.html.ini                  |  6 ---
 .../onerror/not-handled.html.ini              |  6 ---
 .../propagate-to-window-onerror.html.ini      |  6 ---
 .../semantics/multiple-workers/005.html.ini   |  2 +-
 .../semantics/run-a-worker/003.html.ini       |  4 --
 50 files changed, 132 insertions(+), 128 deletions(-)
 delete mode 100644 tests/wpt/metadata/workers/WorkerGlobalScope_ErrorEvent_colno.htm.ini
 delete mode 100644 tests/wpt/metadata/workers/WorkerGlobalScope_ErrorEvent_filename.htm.ini
 delete mode 100644 tests/wpt/metadata/workers/WorkerGlobalScope_ErrorEvent_lineno.htm.ini
 delete mode 100644 tests/wpt/metadata/workers/WorkerGlobalScope_ErrorEvent_message.htm.ini
 delete mode 100644 tests/wpt/metadata/workers/Worker_ErrorEvent_bubbles_cancelable.htm.ini
 delete mode 100644 tests/wpt/metadata/workers/Worker_ErrorEvent_filename.htm.ini
 delete mode 100644 tests/wpt/metadata/workers/Worker_ErrorEvent_lineno.htm.ini
 delete mode 100644 tests/wpt/metadata/workers/Worker_ErrorEvent_message.htm.ini
 delete mode 100644 tests/wpt/metadata/workers/Worker_ErrorEvent_type.htm.ini
 delete mode 100644 tests/wpt/metadata/workers/constructors/Worker/AbstractWorker.onerror.html.ini
 delete mode 100644 tests/wpt/metadata/workers/interfaces/WorkerGlobalScope/onerror/exception-in-onerror.html.ini
 delete mode 100644 tests/wpt/metadata/workers/interfaces/WorkerGlobalScope/onerror/handled.html.ini
 delete mode 100644 tests/wpt/metadata/workers/interfaces/WorkerGlobalScope/onerror/not-handled.html.ini
 delete mode 100644 tests/wpt/metadata/workers/interfaces/WorkerGlobalScope/onerror/propagate-to-window-onerror.html.ini

diff --git a/components/script/dom/bindings/global.rs b/components/script/dom/bindings/global.rs
index 118f04a3c7d..dd03554217d 100644
--- a/components/script/dom/bindings/global.rs
+++ b/components/script/dom/bindings/global.rs
@@ -284,7 +284,7 @@ impl<'a> GlobalRef<'a> {
     pub fn report_an_error(&self, error_info: ErrorInfo, value: HandleValue) {
         match *self {
             GlobalRef::Window(ref window) => window.report_an_error(error_info, value),
-            GlobalRef::Worker(_) => (),
+            GlobalRef::Worker(ref worker) => worker.report_an_error(error_info, value),
         }
     }
 }
diff --git a/components/script/dom/dedicatedworkerglobalscope.rs b/components/script/dom/dedicatedworkerglobalscope.rs
index 1c583fffcc8..b6f6914a50c 100644
--- a/components/script/dom/dedicatedworkerglobalscope.rs
+++ b/components/script/dom/dedicatedworkerglobalscope.rs
@@ -10,15 +10,18 @@ use dom::bindings::cell::DOMRefCell;
 use dom::bindings::codegen::Bindings::DedicatedWorkerGlobalScopeBinding;
 use dom::bindings::codegen::Bindings::DedicatedWorkerGlobalScopeBinding::DedicatedWorkerGlobalScopeMethods;
 use dom::bindings::codegen::Bindings::EventHandlerBinding::EventHandlerNonNull;
-use dom::bindings::error::ErrorResult;
+use dom::bindings::error::{ErrorInfo, ErrorResult};
 use dom::bindings::global::{GlobalRef, global_root_from_context};
 use dom::bindings::inheritance::Castable;
 use dom::bindings::js::{Root, RootCollection};
 use dom::bindings::reflector::Reflectable;
 use dom::bindings::str::DOMString;
 use dom::bindings::structuredclone::StructuredCloneData;
+use dom::errorevent::ErrorEvent;
+use dom::event::{Event, EventBubbles, EventCancelable};
+use dom::eventtarget::EventTarget;
 use dom::messageevent::MessageEvent;
-use dom::worker::{TrustedWorkerAddress, WorkerMessageHandler};
+use dom::worker::{TrustedWorkerAddress, WorkerErrorHandler, WorkerMessageHandler};
 use dom::workerglobalscope::WorkerGlobalScope;
 use ipc_channel::ipc::{self, IpcReceiver, IpcSender};
 use ipc_channel::router::ROUTER;
@@ -32,6 +35,7 @@ use rand::random;
 use script_runtime::{CommonScriptMsg, ScriptChan, ScriptPort, StackRootTLS, get_reports, new_rt_and_cx};
 use script_runtime::ScriptThreadEventCategory::WorkerEvent;
 use script_traits::{TimerEvent, TimerSource, WorkerGlobalScopeInit, WorkerScriptLoadOrigin};
+use std::cell::Cell;
 use std::mem::replace;
 use std::sync::{Arc, Mutex};
 use std::sync::atomic::AtomicBool;
@@ -88,6 +92,8 @@ pub struct DedicatedWorkerGlobalScope {
     #[ignore_heap_size_of = "Can't measure trait objects"]
     /// Sender to the parent thread.
     parent_sender: Box<ScriptChan + Send>,
+    /// https://html.spec.whatwg.org/multipage/#in-error-reporting-mode
+    in_error_reporting_mode: Cell<bool>
 }
 
 impl DedicatedWorkerGlobalScope {
@@ -116,6 +122,7 @@ impl DedicatedWorkerGlobalScope {
             timer_event_port: timer_event_port,
             parent_sender: parent_sender,
             worker: DOMRefCell::new(None),
+            in_error_reporting_mode: Cell::new(false),
         }
     }
 
@@ -339,6 +346,41 @@ impl DedicatedWorkerGlobalScope {
             }
         }
     }
+
+    /// https://html.spec.whatwg.org/multipage/#report-the-error
+    pub fn report_an_error(&self, error_info: ErrorInfo, value: HandleValue) {
+        // Step 1.
+        if self.in_error_reporting_mode.get() {
+            return;
+        }
+
+        // Step 2.
+        self.in_error_reporting_mode.set(true);
+
+        // Steps 3-12.
+        let event = ErrorEvent::new(GlobalRef::Worker(self.upcast()),
+                                    atom!("error"),
+                                    EventBubbles::DoesNotBubble,
+                                    EventCancelable::Cancelable,
+                                    error_info.message.as_str().into(),
+                                    error_info.filename.as_str().into(),
+                                    error_info.lineno,
+                                    error_info.column,
+                                    value);
+
+        // Step 13.
+        let handled = !event.upcast::<Event>().fire(self.upcast::<EventTarget>());
+        if !handled {
+            let worker = self.worker.borrow().as_ref().unwrap().clone();
+            // TODO: Should use the DOM manipulation task source.
+            self.parent_sender
+                .send(CommonScriptMsg::RunnableMsg(WorkerEvent,
+                                                   box WorkerErrorHandler::new(worker, error_info)))
+                .unwrap();
+        }
+
+        self.in_error_reporting_mode.set(false);
+    }
 }
 
 #[allow(unsafe_code)]
diff --git a/components/script/dom/webidls/WorkerGlobalScope.webidl b/components/script/dom/webidls/WorkerGlobalScope.webidl
index ec65bcb09a6..cc9fb292cd3 100644
--- a/components/script/dom/webidls/WorkerGlobalScope.webidl
+++ b/components/script/dom/webidls/WorkerGlobalScope.webidl
@@ -9,7 +9,7 @@ interface WorkerGlobalScope : EventTarget {
   readonly attribute WorkerLocation location;
 
   //void close();
-  //         attribute OnErrorEventHandler onerror;
+  attribute OnErrorEventHandler onerror;
   //         attribute EventHandler onlanguagechange;
   //         attribute EventHandler onoffline;
   //         attribute EventHandler ononline;
diff --git a/components/script/dom/worker.rs b/components/script/dom/worker.rs
index 938ca28c148..e40ebee24f0 100644
--- a/components/script/dom/worker.rs
+++ b/components/script/dom/worker.rs
@@ -8,7 +8,7 @@ use dom::abstractworker::WorkerScriptMsg;
 use dom::bindings::codegen::Bindings::EventHandlerBinding::EventHandlerNonNull;
 use dom::bindings::codegen::Bindings::WorkerBinding;
 use dom::bindings::codegen::Bindings::WorkerBinding::WorkerMethods;
-use dom::bindings::error::{Error, ErrorResult, Fallible};
+use dom::bindings::error::{Error, ErrorResult, Fallible, ErrorInfo};
 use dom::bindings::global::GlobalRef;
 use dom::bindings::inheritance::Castable;
 use dom::bindings::js::Root;
@@ -17,11 +17,13 @@ use dom::bindings::reflector::{Reflectable, reflect_dom_object};
 use dom::bindings::str::DOMString;
 use dom::bindings::structuredclone::StructuredCloneData;
 use dom::dedicatedworkerglobalscope::DedicatedWorkerGlobalScope;
+use dom::errorevent::ErrorEvent;
+use dom::event::{Event, EventBubbles, EventCancelable};
 use dom::eventtarget::EventTarget;
 use dom::messageevent::MessageEvent;
 use dom::workerglobalscope::prepare_workerscope_init;
 use ipc_channel::ipc;
-use js::jsapi::{HandleValue, JSAutoCompartment, JSContext};
+use js::jsapi::{HandleValue, JSAutoCompartment, JSContext, NullHandleValue};
 use js::jsval::UndefinedValue;
 use script_thread::Runnable;
 use script_traits::WorkerScriptLoadOrigin;
@@ -137,6 +139,26 @@ impl Worker {
         let worker = address.root();
         worker.upcast().fire_simple_event("error");
     }
+
+    fn dispatch_error(&self, error_info: ErrorInfo) {
+        let global = self.global();
+        let event = ErrorEvent::new(global.r(),
+                                    atom!("error"),
+                                    EventBubbles::DoesNotBubble,
+                                    EventCancelable::Cancelable,
+                                    error_info.message.as_str().into(),
+                                    error_info.filename.as_str().into(),
+                                    error_info.lineno,
+                                    error_info.column,
+                                    NullHandleValue);
+
+        let handled = !event.upcast::<Event>().fire(self.upcast::<EventTarget>());
+        if handled {
+            return;
+        }
+
+        global.r().report_an_error(error_info, NullHandleValue);
+    }
 }
 
 impl WorkerMethods for Worker {
@@ -202,3 +224,24 @@ impl Runnable for SimpleWorkerErrorHandler<Worker> {
         Worker::dispatch_simple_error(this.addr);
     }
 }
+
+pub struct WorkerErrorHandler {
+    address: Trusted<Worker>,
+    error_info: ErrorInfo,
+}
+
+impl WorkerErrorHandler {
+    pub fn new(address: Trusted<Worker>, error_info: ErrorInfo) -> WorkerErrorHandler {
+        WorkerErrorHandler {
+            address: address,
+            error_info: error_info,
+        }
+    }
+}
+
+impl Runnable for WorkerErrorHandler {
+    fn handler(self: Box<Self>) {
+        let this = *self;
+        this.address.root().dispatch_error(this.error_info);
+    }
+}
diff --git a/components/script/dom/workerglobalscope.rs b/components/script/dom/workerglobalscope.rs
index 18f51156aec..d60ddb84f88 100644
--- a/components/script/dom/workerglobalscope.rs
+++ b/components/script/dom/workerglobalscope.rs
@@ -3,9 +3,10 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 use devtools_traits::{DevtoolScriptControlMsg, ScriptToDevtoolsControlMsg, WorkerId};
+use dom::bindings::codegen::Bindings::EventHandlerBinding::OnErrorEventHandlerNonNull;
 use dom::bindings::codegen::Bindings::FunctionBinding::Function;
 use dom::bindings::codegen::Bindings::WorkerGlobalScopeBinding::WorkerGlobalScopeMethods;
-use dom::bindings::error::{Error, ErrorResult, Fallible, report_pending_exception};
+use dom::bindings::error::{Error, ErrorResult, Fallible, report_pending_exception, ErrorInfo};
 use dom::bindings::global::GlobalRef;
 use dom::bindings::inheritance::Castable;
 use dom::bindings::js::{JS, MutNullableHeap, Root};
@@ -248,6 +249,9 @@ impl WorkerGlobalScopeMethods for WorkerGlobalScope {
         })
     }
 
+    // https://html.spec.whatwg.org/multipage/#handler-workerglobalscope-onerror
+    error_event_handler!(error, GetOnerror, SetOnerror);
+
     // https://html.spec.whatwg.org/multipage/#dom-workerglobalscope-importscripts
     fn ImportScripts(&self, url_strings: Vec<DOMString>) -> ErrorResult {
         let mut urls = Vec::with_capacity(url_strings.len());
@@ -451,4 +455,11 @@ impl WorkerGlobalScope {
             closing.store(true, Ordering::SeqCst);
         }
     }
+
+    /// https://html.spec.whatwg.org/multipage/#report-the-error
+    pub fn report_an_error(&self, error_info: ErrorInfo, value: HandleValue) {
+        self.downcast::<DedicatedWorkerGlobalScope>()
+            .expect("Should implement report_an_error for this worker")
+            .report_an_error(error_info, value);
+    }
 }
diff --git a/tests/wpt/metadata/WebCryptoAPI/digest/digest.worker.js.ini b/tests/wpt/metadata/WebCryptoAPI/digest/digest.worker.js.ini
index 3a3037f6888..fc3de2fa61a 100644
--- a/tests/wpt/metadata/WebCryptoAPI/digest/digest.worker.js.ini
+++ b/tests/wpt/metadata/WebCryptoAPI/digest/digest.worker.js.ini
@@ -1,6 +1,6 @@
 [digest.worker]
   type: testharness
-  expected: TIMEOUT
+  expected: ERROR
   [SHA-1 with empty source data]
     expected: FAIL
 
diff --git a/tests/wpt/metadata/WebCryptoAPI/encrypt_decrypt/aes_cbc.worker.js.ini b/tests/wpt/metadata/WebCryptoAPI/encrypt_decrypt/aes_cbc.worker.js.ini
index 31535209e25..ad9373e870d 100644
--- a/tests/wpt/metadata/WebCryptoAPI/encrypt_decrypt/aes_cbc.worker.js.ini
+++ b/tests/wpt/metadata/WebCryptoAPI/encrypt_decrypt/aes_cbc.worker.js.ini
@@ -1,3 +1,3 @@
 [aes_cbc.worker]
   type: testharness
-  expected: TIMEOUT
+  expected: ERROR
diff --git a/tests/wpt/metadata/WebCryptoAPI/encrypt_decrypt/aes_ctr.worker.js.ini b/tests/wpt/metadata/WebCryptoAPI/encrypt_decrypt/aes_ctr.worker.js.ini
index 5fa0adcf75f..b65f0a6d0f5 100644
--- a/tests/wpt/metadata/WebCryptoAPI/encrypt_decrypt/aes_ctr.worker.js.ini
+++ b/tests/wpt/metadata/WebCryptoAPI/encrypt_decrypt/aes_ctr.worker.js.ini
@@ -1,3 +1,3 @@
 [aes_ctr.worker]
   type: testharness
-  expected: TIMEOUT
+  expected: ERROR
diff --git a/tests/wpt/metadata/WebCryptoAPI/encrypt_decrypt/aes_gcm.worker.js.ini b/tests/wpt/metadata/WebCryptoAPI/encrypt_decrypt/aes_gcm.worker.js.ini
index d4191552762..a576b4e021b 100644
--- a/tests/wpt/metadata/WebCryptoAPI/encrypt_decrypt/aes_gcm.worker.js.ini
+++ b/tests/wpt/metadata/WebCryptoAPI/encrypt_decrypt/aes_gcm.worker.js.ini
@@ -1,3 +1,3 @@
 [aes_gcm.worker]
   type: testharness
-  expected: TIMEOUT
+  expected: ERROR
diff --git a/tests/wpt/metadata/WebCryptoAPI/encrypt_decrypt/rsa.worker.js.ini b/tests/wpt/metadata/WebCryptoAPI/encrypt_decrypt/rsa.worker.js.ini
index db93f4356d6..addfa4b287f 100644
--- a/tests/wpt/metadata/WebCryptoAPI/encrypt_decrypt/rsa.worker.js.ini
+++ b/tests/wpt/metadata/WebCryptoAPI/encrypt_decrypt/rsa.worker.js.ini
@@ -1,3 +1,3 @@
 [rsa.worker]
   type: testharness
-  expected: TIMEOUT
+  expected: ERROR
diff --git a/tests/wpt/metadata/WebCryptoAPI/generateKey/failures.worker.js.ini b/tests/wpt/metadata/WebCryptoAPI/generateKey/failures.worker.js.ini
index 36690a4f41c..1e4aabbea47 100644
--- a/tests/wpt/metadata/WebCryptoAPI/generateKey/failures.worker.js.ini
+++ b/tests/wpt/metadata/WebCryptoAPI/generateKey/failures.worker.js.ini
@@ -1,3 +1,3 @@
 [failures.worker]
   type: testharness
-  expected: TIMEOUT
+  expected: ERROR
diff --git a/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_AES-CBC.worker.js.ini b/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_AES-CBC.worker.js.ini
index ee42669a8b5..7b3310b78b5 100644
--- a/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_AES-CBC.worker.js.ini
+++ b/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_AES-CBC.worker.js.ini
@@ -1,3 +1,3 @@
 [failures_AES-CBC.worker]
   type: testharness
-  expected: TIMEOUT
+  expected: ERROR
diff --git a/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_AES-CTR.worker.js.ini b/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_AES-CTR.worker.js.ini
index b6e622df5a5..472b09dd1ee 100644
--- a/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_AES-CTR.worker.js.ini
+++ b/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_AES-CTR.worker.js.ini
@@ -1,3 +1,3 @@
 [failures_AES-CTR.worker]
   type: testharness
-  expected: TIMEOUT
+  expected: ERROR
diff --git a/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_AES-GCM.worker.js.ini b/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_AES-GCM.worker.js.ini
index 875108ec411..64e9f58f061 100644
--- a/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_AES-GCM.worker.js.ini
+++ b/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_AES-GCM.worker.js.ini
@@ -1,3 +1,3 @@
 [failures_AES-GCM.worker]
   type: testharness
-  expected: TIMEOUT
+  expected: ERROR
diff --git a/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_AES-KW.worker.js.ini b/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_AES-KW.worker.js.ini
index 5a6535ba83b..96031ce55c3 100644
--- a/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_AES-KW.worker.js.ini
+++ b/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_AES-KW.worker.js.ini
@@ -1,3 +1,3 @@
 [failures_AES-KW.worker]
   type: testharness
-  expected: TIMEOUT
+  expected: ERROR
diff --git a/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_ECDH.worker.js.ini b/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_ECDH.worker.js.ini
index 433faeb8a1e..49ab628294f 100644
--- a/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_ECDH.worker.js.ini
+++ b/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_ECDH.worker.js.ini
@@ -1,3 +1,3 @@
 [failures_ECDH.worker]
   type: testharness
-  expected: TIMEOUT
+  expected: ERROR
diff --git a/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_ECDSA.worker.js.ini b/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_ECDSA.worker.js.ini
index 7c2e8989e50..2fd250f4500 100644
--- a/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_ECDSA.worker.js.ini
+++ b/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_ECDSA.worker.js.ini
@@ -1,3 +1,3 @@
 [failures_ECDSA.worker]
   type: testharness
-  expected: TIMEOUT
+  expected: ERROR
diff --git a/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_HMAC.worker.js.ini b/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_HMAC.worker.js.ini
index faf7cfd60d6..411ecbddac9 100644
--- a/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_HMAC.worker.js.ini
+++ b/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_HMAC.worker.js.ini
@@ -1,3 +1,3 @@
 [failures_HMAC.worker]
   type: testharness
-  expected: TIMEOUT
+  expected: ERROR
diff --git a/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_RSA-OAEP.worker.js.ini b/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_RSA-OAEP.worker.js.ini
index baed1d704c0..3ec9c3c5388 100644
--- a/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_RSA-OAEP.worker.js.ini
+++ b/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_RSA-OAEP.worker.js.ini
@@ -1,3 +1,3 @@
 [failures_RSA-OAEP.worker]
   type: testharness
-  expected: TIMEOUT
+  expected: ERROR
diff --git a/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_RSA-PSS.worker.js.ini b/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_RSA-PSS.worker.js.ini
index 02f03d007fb..7b28b2c0480 100644
--- a/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_RSA-PSS.worker.js.ini
+++ b/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_RSA-PSS.worker.js.ini
@@ -1,3 +1,3 @@
 [failures_RSA-PSS.worker]
   type: testharness
-  expected: TIMEOUT
+  expected: ERROR
diff --git a/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_RSASSA-PKCS1-v1_5.worker.js.ini b/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_RSASSA-PKCS1-v1_5.worker.js.ini
index 4faf5a9516f..5cb45ae095b 100644
--- a/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_RSASSA-PKCS1-v1_5.worker.js.ini
+++ b/tests/wpt/metadata/WebCryptoAPI/generateKey/failures_RSASSA-PKCS1-v1_5.worker.js.ini
@@ -1,3 +1,3 @@
 [failures_RSASSA-PKCS1-v1_5.worker]
   type: testharness
-  expected: TIMEOUT
+  expected: ERROR
diff --git a/tests/wpt/metadata/WebCryptoAPI/generateKey/successes.worker.js.ini b/tests/wpt/metadata/WebCryptoAPI/generateKey/successes.worker.js.ini
index 40b0d52323b..f3a7d610c37 100644
--- a/tests/wpt/metadata/WebCryptoAPI/generateKey/successes.worker.js.ini
+++ b/tests/wpt/metadata/WebCryptoAPI/generateKey/successes.worker.js.ini
@@ -1,3 +1,3 @@
 [successes.worker]
   type: testharness
-  expected: TIMEOUT
+  expected: ERROR
diff --git a/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_AES-CBC.worker.js.ini b/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_AES-CBC.worker.js.ini
index 8c2bf86074d..e9a9e303a25 100644
--- a/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_AES-CBC.worker.js.ini
+++ b/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_AES-CBC.worker.js.ini
@@ -1,3 +1,3 @@
 [successes_AES-CBC.worker]
   type: testharness
-  expected: TIMEOUT
+  expected: ERROR
diff --git a/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_AES-CTR.worker.js.ini b/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_AES-CTR.worker.js.ini
index 81be2d58552..dcf7febafe5 100644
--- a/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_AES-CTR.worker.js.ini
+++ b/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_AES-CTR.worker.js.ini
@@ -1,3 +1,3 @@
 [successes_AES-CTR.worker]
   type: testharness
-  expected: TIMEOUT
+  expected: ERROR
diff --git a/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_AES-GCM.worker.js.ini b/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_AES-GCM.worker.js.ini
index 2737b6e9354..4b949a1b47d 100644
--- a/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_AES-GCM.worker.js.ini
+++ b/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_AES-GCM.worker.js.ini
@@ -1,3 +1,3 @@
 [successes_AES-GCM.worker]
   type: testharness
-  expected: TIMEOUT
+  expected: ERROR
diff --git a/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_AES-KW.worker.js.ini b/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_AES-KW.worker.js.ini
index 82c15a8f6d8..5efa92cfc5d 100644
--- a/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_AES-KW.worker.js.ini
+++ b/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_AES-KW.worker.js.ini
@@ -1,3 +1,3 @@
 [successes_AES-KW.worker]
   type: testharness
-  expected: TIMEOUT
+  expected: ERROR
diff --git a/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_ECDH.worker.js.ini b/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_ECDH.worker.js.ini
index e091c4ad31a..42eac719df6 100644
--- a/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_ECDH.worker.js.ini
+++ b/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_ECDH.worker.js.ini
@@ -1,3 +1,3 @@
 [successes_ECDH.worker]
   type: testharness
-  expected: TIMEOUT
+  expected: ERROR
diff --git a/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_ECDSA.worker.js.ini b/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_ECDSA.worker.js.ini
index f0d3b7c3534..0d73e197cf9 100644
--- a/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_ECDSA.worker.js.ini
+++ b/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_ECDSA.worker.js.ini
@@ -1,3 +1,3 @@
 [successes_ECDSA.worker]
   type: testharness
-  expected: TIMEOUT
+  expected: ERROR
diff --git a/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_HMAC.worker.js.ini b/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_HMAC.worker.js.ini
index b7a96c8048d..84b2544fd81 100644
--- a/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_HMAC.worker.js.ini
+++ b/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_HMAC.worker.js.ini
@@ -1,3 +1,3 @@
 [successes_HMAC.worker]
   type: testharness
-  expected: TIMEOUT
+  expected: ERROR
diff --git a/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_RSA-OAEP.worker.js.ini b/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_RSA-OAEP.worker.js.ini
index 8617753c200..f4e683fa2df 100644
--- a/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_RSA-OAEP.worker.js.ini
+++ b/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_RSA-OAEP.worker.js.ini
@@ -1,3 +1,3 @@
 [successes_RSA-OAEP.worker]
   type: testharness
-  expected: TIMEOUT
+  expected: ERROR
diff --git a/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_RSA-PSS.worker.js.ini b/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_RSA-PSS.worker.js.ini
index 3c04506e2a5..76a09318544 100644
--- a/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_RSA-PSS.worker.js.ini
+++ b/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_RSA-PSS.worker.js.ini
@@ -1,3 +1,3 @@
 [successes_RSA-PSS.worker]
   type: testharness
-  expected: TIMEOUT
+  expected: ERROR
diff --git a/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_RSASSA-PKCS1-v1_5.worker.js.ini b/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_RSASSA-PKCS1-v1_5.worker.js.ini
index 72b6ac43d86..95acb89f629 100644
--- a/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_RSASSA-PKCS1-v1_5.worker.js.ini
+++ b/tests/wpt/metadata/WebCryptoAPI/generateKey/successes_RSASSA-PKCS1-v1_5.worker.js.ini
@@ -1,3 +1,3 @@
 [successes_RSASSA-PKCS1-v1_5.worker]
   type: testharness
-  expected: TIMEOUT
+  expected: ERROR
diff --git a/tests/wpt/metadata/workers/WorkerGlobalScope_ErrorEvent_colno.htm.ini b/tests/wpt/metadata/workers/WorkerGlobalScope_ErrorEvent_colno.htm.ini
deleted file mode 100644
index 158e473da7a..00000000000
--- a/tests/wpt/metadata/workers/WorkerGlobalScope_ErrorEvent_colno.htm.ini
+++ /dev/null
@@ -1,6 +0,0 @@
-[WorkerGlobalScope_ErrorEvent_colno.htm]
-  type: testharness
-  expected: TIMEOUT
-  [ WorkerGlobalScope onerror event handler argument: col ]
-    expected: TIMEOUT
-
diff --git a/tests/wpt/metadata/workers/WorkerGlobalScope_ErrorEvent_filename.htm.ini b/tests/wpt/metadata/workers/WorkerGlobalScope_ErrorEvent_filename.htm.ini
deleted file mode 100644
index 8f4d379cfc5..00000000000
--- a/tests/wpt/metadata/workers/WorkerGlobalScope_ErrorEvent_filename.htm.ini
+++ /dev/null
@@ -1,6 +0,0 @@
-[WorkerGlobalScope_ErrorEvent_filename.htm]
-  type: testharness
-  expected: TIMEOUT
-  [ WorkerGlobalScope onerror event handler argument: location ]
-    expected: TIMEOUT
-
diff --git a/tests/wpt/metadata/workers/WorkerGlobalScope_ErrorEvent_lineno.htm.ini b/tests/wpt/metadata/workers/WorkerGlobalScope_ErrorEvent_lineno.htm.ini
deleted file mode 100644
index 73f26d8f9b9..00000000000
--- a/tests/wpt/metadata/workers/WorkerGlobalScope_ErrorEvent_lineno.htm.ini
+++ /dev/null
@@ -1,6 +0,0 @@
-[WorkerGlobalScope_ErrorEvent_lineno.htm]
-  type: testharness
-  expected: TIMEOUT
-  [ WorkerGlobalScope onerror event handler argument: line ]
-    expected: TIMEOUT
-
diff --git a/tests/wpt/metadata/workers/WorkerGlobalScope_ErrorEvent_message.htm.ini b/tests/wpt/metadata/workers/WorkerGlobalScope_ErrorEvent_message.htm.ini
deleted file mode 100644
index 7e13c7b35b0..00000000000
--- a/tests/wpt/metadata/workers/WorkerGlobalScope_ErrorEvent_message.htm.ini
+++ /dev/null
@@ -1,6 +0,0 @@
-[WorkerGlobalScope_ErrorEvent_message.htm]
-  type: testharness
-  expected: TIMEOUT
-  [ WorkerGlobalScope onerror event handler argument: message ]
-    expected: TIMEOUT
-
diff --git a/tests/wpt/metadata/workers/Worker_ErrorEvent_bubbles_cancelable.htm.ini b/tests/wpt/metadata/workers/Worker_ErrorEvent_bubbles_cancelable.htm.ini
deleted file mode 100644
index b5171d68e02..00000000000
--- a/tests/wpt/metadata/workers/Worker_ErrorEvent_bubbles_cancelable.htm.ini
+++ /dev/null
@@ -1,6 +0,0 @@
-[Worker_ErrorEvent_bubbles_cancelable.htm]
-  type: testharness
-  expected: TIMEOUT
-  [ErrorEvent on worker doesn't bubble and is cancelable]
-    expected: TIMEOUT
-
diff --git a/tests/wpt/metadata/workers/Worker_ErrorEvent_filename.htm.ini b/tests/wpt/metadata/workers/Worker_ErrorEvent_filename.htm.ini
deleted file mode 100644
index 22fd38a7328..00000000000
--- a/tests/wpt/metadata/workers/Worker_ErrorEvent_filename.htm.ini
+++ /dev/null
@@ -1,6 +0,0 @@
-[Worker_ErrorEvent_filename.htm]
-  type: testharness
-  expected: TIMEOUT
-  [ AbstractWorker ErrorEvent.filename ]
-    expected: TIMEOUT
-
diff --git a/tests/wpt/metadata/workers/Worker_ErrorEvent_lineno.htm.ini b/tests/wpt/metadata/workers/Worker_ErrorEvent_lineno.htm.ini
deleted file mode 100644
index 91f945e647c..00000000000
--- a/tests/wpt/metadata/workers/Worker_ErrorEvent_lineno.htm.ini
+++ /dev/null
@@ -1,6 +0,0 @@
-[Worker_ErrorEvent_lineno.htm]
-  type: testharness
-  expected: TIMEOUT
-  [ AbstractWorker ErrorEvent.lineno ]
-    expected: TIMEOUT
-
diff --git a/tests/wpt/metadata/workers/Worker_ErrorEvent_message.htm.ini b/tests/wpt/metadata/workers/Worker_ErrorEvent_message.htm.ini
deleted file mode 100644
index 51293d0268c..00000000000
--- a/tests/wpt/metadata/workers/Worker_ErrorEvent_message.htm.ini
+++ /dev/null
@@ -1,6 +0,0 @@
-[Worker_ErrorEvent_message.htm]
-  type: testharness
-  expected: TIMEOUT
-  [ AbstractWorker ErrorEvent.message ]
-    expected: TIMEOUT
-
diff --git a/tests/wpt/metadata/workers/Worker_ErrorEvent_type.htm.ini b/tests/wpt/metadata/workers/Worker_ErrorEvent_type.htm.ini
deleted file mode 100644
index bd8fa115835..00000000000
--- a/tests/wpt/metadata/workers/Worker_ErrorEvent_type.htm.ini
+++ /dev/null
@@ -1,6 +0,0 @@
-[Worker_ErrorEvent_type.htm]
-  type: testharness
-  expected: TIMEOUT
-  [ AbstractWorker ErrorEvent.type ]
-    expected: TIMEOUT
-
diff --git a/tests/wpt/metadata/workers/baseurl/alpha/sharedworker.html.ini b/tests/wpt/metadata/workers/baseurl/alpha/sharedworker.html.ini
index e4c8d44755f..de9df5b161e 100644
--- a/tests/wpt/metadata/workers/baseurl/alpha/sharedworker.html.ini
+++ b/tests/wpt/metadata/workers/baseurl/alpha/sharedworker.html.ini
@@ -1,6 +1,5 @@
 [sharedworker.html]
   type: testharness
-  expected: TIMEOUT
   [Base URL in workers: new SharedWorker()]
-    expected: TIMEOUT
+    expected: FAIL
 
diff --git a/tests/wpt/metadata/workers/constructors/Worker/AbstractWorker.onerror.html.ini b/tests/wpt/metadata/workers/constructors/Worker/AbstractWorker.onerror.html.ini
deleted file mode 100644
index d847fee7777..00000000000
--- a/tests/wpt/metadata/workers/constructors/Worker/AbstractWorker.onerror.html.ini
+++ /dev/null
@@ -1,6 +0,0 @@
-[AbstractWorker.onerror.html]
-  type: testharness
-  expected: TIMEOUT
-  [AbstractWorker.onerror]
-    expected: TIMEOUT
-
diff --git a/tests/wpt/metadata/workers/interfaces.worker.js.ini b/tests/wpt/metadata/workers/interfaces.worker.js.ini
index eddc260926b..9111901ba73 100644
--- a/tests/wpt/metadata/workers/interfaces.worker.js.ini
+++ b/tests/wpt/metadata/workers/interfaces.worker.js.ini
@@ -21,9 +21,6 @@
   [DedicatedWorkerGlobalScope interface: attribute onmessage]
     expected: FAIL
 
-  [WorkerGlobalScope interface: self must inherit property "onerror" with the proper type (3)]
-    expected: FAIL
-
   [WorkerGlobalScope interface: self must inherit property "onlanguagechange" with the proper type (4)]
     expected: FAIL
 
diff --git a/tests/wpt/metadata/workers/interfaces/WorkerGlobalScope/onerror/exception-in-onerror.html.ini b/tests/wpt/metadata/workers/interfaces/WorkerGlobalScope/onerror/exception-in-onerror.html.ini
deleted file mode 100644
index 17f23fe3030..00000000000
--- a/tests/wpt/metadata/workers/interfaces/WorkerGlobalScope/onerror/exception-in-onerror.html.ini
+++ /dev/null
@@ -1,6 +0,0 @@
-[exception-in-onerror.html]
-  type: testharness
-  expected: TIMEOUT
-  [onerror, "not handled" with an error in the onerror function]
-    expected: TIMEOUT
-
diff --git a/tests/wpt/metadata/workers/interfaces/WorkerGlobalScope/onerror/handled.html.ini b/tests/wpt/metadata/workers/interfaces/WorkerGlobalScope/onerror/handled.html.ini
deleted file mode 100644
index 2a533abd72a..00000000000
--- a/tests/wpt/metadata/workers/interfaces/WorkerGlobalScope/onerror/handled.html.ini
+++ /dev/null
@@ -1,6 +0,0 @@
-[handled.html]
-  type: testharness
-  expected: TIMEOUT
-  [onerror, "handled"]
-    expected: TIMEOUT
-
diff --git a/tests/wpt/metadata/workers/interfaces/WorkerGlobalScope/onerror/not-handled.html.ini b/tests/wpt/metadata/workers/interfaces/WorkerGlobalScope/onerror/not-handled.html.ini
deleted file mode 100644
index e2c53cad484..00000000000
--- a/tests/wpt/metadata/workers/interfaces/WorkerGlobalScope/onerror/not-handled.html.ini
+++ /dev/null
@@ -1,6 +0,0 @@
-[not-handled.html]
-  type: testharness
-  expected: TIMEOUT
-  [onerror, "not handled"]
-    expected: TIMEOUT
-
diff --git a/tests/wpt/metadata/workers/interfaces/WorkerGlobalScope/onerror/propagate-to-window-onerror.html.ini b/tests/wpt/metadata/workers/interfaces/WorkerGlobalScope/onerror/propagate-to-window-onerror.html.ini
deleted file mode 100644
index 508a59a7c22..00000000000
--- a/tests/wpt/metadata/workers/interfaces/WorkerGlobalScope/onerror/propagate-to-window-onerror.html.ini
+++ /dev/null
@@ -1,6 +0,0 @@
-[propagate-to-window-onerror.html]
-  type: testharness
-  expected: TIMEOUT
-  [onerror, "not handled" with only window.onerror defined]
-    expected: TIMEOUT
-
diff --git a/tests/wpt/metadata/workers/semantics/multiple-workers/005.html.ini b/tests/wpt/metadata/workers/semantics/multiple-workers/005.html.ini
index b4ceb9bc7f6..c9d56df44bc 100644
--- a/tests/wpt/metadata/workers/semantics/multiple-workers/005.html.ini
+++ b/tests/wpt/metadata/workers/semantics/multiple-workers/005.html.ini
@@ -1,6 +1,6 @@
 [005.html]
   type: testharness
-  expected: TIMEOUT
+  expected: ERROR
   [dedicated worker in shared worker in dedicated worker]
     expected: TIMEOUT
 
diff --git a/tests/wpt/metadata/workers/semantics/run-a-worker/003.html.ini b/tests/wpt/metadata/workers/semantics/run-a-worker/003.html.ini
index 132189cae6e..d6e39444229 100644
--- a/tests/wpt/metadata/workers/semantics/run-a-worker/003.html.ini
+++ b/tests/wpt/metadata/workers/semantics/run-a-worker/003.html.ini
@@ -1,9 +1,5 @@
 [003.html]
   type: testharness
-  expected: TIMEOUT
-  [worker]
-    expected: TIMEOUT
-
   [shared]
     expected: FAIL
 

From 3978359b43da0da4f717aa93913524691632123a Mon Sep 17 00:00:00 2001
From: Ms2ger <Ms2ger@gmail.com>
Date: Wed, 7 Sep 2016 11:15:23 +0200
Subject: [PATCH 3/3] Note the lacking support for muted errors.

---
 components/script/dom/dedicatedworkerglobalscope.rs | 1 +
 components/script/dom/window.rs                     | 1 +
 2 files changed, 2 insertions(+)

diff --git a/components/script/dom/dedicatedworkerglobalscope.rs b/components/script/dom/dedicatedworkerglobalscope.rs
index b6f6914a50c..4f0bad72949 100644
--- a/components/script/dom/dedicatedworkerglobalscope.rs
+++ b/components/script/dom/dedicatedworkerglobalscope.rs
@@ -358,6 +358,7 @@ impl DedicatedWorkerGlobalScope {
         self.in_error_reporting_mode.set(true);
 
         // Steps 3-12.
+        // FIXME(#13195): muted errors.
         let event = ErrorEvent::new(GlobalRef::Worker(self.upcast()),
                                     atom!("error"),
                                     EventBubbles::DoesNotBubble,
diff --git a/components/script/dom/window.rs b/components/script/dom/window.rs
index e28b381a2fa..4954f7cccd0 100644
--- a/components/script/dom/window.rs
+++ b/components/script/dom/window.rs
@@ -1766,6 +1766,7 @@ impl Window {
         self.in_error_reporting_mode.set(true);
 
         // Steps 3-12.
+        // FIXME(#13195): muted errors.
         let event = ErrorEvent::new(GlobalRef::Window(self),
                                     atom!("error"),
                                     EventBubbles::DoesNotBubble,