Unset CompositorWorkerGlobalScope during WorkerGlobalScope::dipose.

third_party/WebKit/Source/modules/compositorworker/CompositorWorkerGlobalScope.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "modules/compositorworker/CompositorWorkerGlobalScope.h"
 
 #include "bindings/core/v8/SerializedScriptValue.h"
 #include "core/workers/InProcessWorkerObjectProxy.h"
 #include "core/workers/WorkerThreadStartupData.h"
 #include "modules/EventTargetModules.h"
@@ skipping 31 matching lines @@
 {
     visitor->trace(m_callbackCollection);
     WorkerGlobalScope::trace(visitor);
 }
 
 const AtomicString& CompositorWorkerGlobalScope::interfaceName() const
 {
     return EventTargetNames::CompositorWorkerGlobalScope;
 }
 
+void CompositorWorkerGlobalScope::removeAllEventListeners()
+{
+    // Note, we may still have callbacks in m_callbackCollection, but this
+    // ensures that we will no longer try to call them after this global
+    // scope has been disposed.
+    CompositorProxyClient::from(clients())->setGlobalScope(nullptr);
+}
+
 void CompositorWorkerGlobalScope::postMessage(ExecutionContext* executionContext, PassRefPtr<SerializedScriptValue> message, const MessagePortArray& ports, ExceptionState& exceptionState)
 {
     // Disentangle the port in preparation for sending it to the remote context.
     std::unique_ptr<MessagePortChannelArray> channels = MessagePort::disentanglePorts(executionContext, ports, exceptionState);
     if (exceptionState.hadException())
         return;
     thread()->workerObjectProxy().postMessageToWorkerObject(std::move(message), std::move(channels));
 }
 
 int CompositorWorkerGlobalScope::requestAnimationFrame(FrameRequestCallback* callback)
@@ skipping 15 matching lines @@
     m_callbackCollection.executeCallbacks(highResTimeMs, highResTimeMs);
     return !m_callbackCollection.isEmpty();
 }
 
 CompositorWorkerThread* CompositorWorkerGlobalScope::thread() const
 {
     return static_cast<CompositorWorkerThread*>(WorkerGlobalScope::thread());
 }
 
 } // namespace blink