compositor-worker: Initialize CW machinery plumbing to compositor and fire CW rAF callbacks.

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 38 matching lines @@
 {
     // Disentangle the port in preparation for sending it to the remote context.
     OwnPtr<MessagePortChannelArray> channels = MessagePort::disentanglePorts(executionContext, ports, exceptionState);
     if (exceptionState.hadException())
         return;
     thread()->workerObjectProxy().postMessageToWorkerObject(message, std::move(channels));
 }
 
 int CompositorWorkerGlobalScope::requestAnimationFrame(FrameRequestCallback* callback)
 {
-    // For now, just post a task to call mutate on the compositor proxy client.
-    // TODO(flackr): Remove this as soon as CompositorProxyClient can request a
-    // compositor frame from the CompositorMutatorImpl.
-    thread()->postTask(BLINK_FROM_HERE, createSameThreadTask(&CompositorProxyClient::runAnimationFrameCallbacks,
-        CompositorProxyClient::from(clients())));
-    // TODO(flackr): Signal the compositor to call mutate on the next compositor frame.
+    const bool shouldSignal = !m_executingAnimationFrameCallbacks && m_callbackCollection.isEmpty();
+    if (shouldSignal)
+        CompositorProxyClient::from(clients())->requestAnimationFrame();
     return m_callbackCollection.registerCallback(callback);
 }
 
 void CompositorWorkerGlobalScope::cancelAnimationFrame(int id)
 {
     m_callbackCollection.cancelCallback(id);
 }
 
 bool CompositorWorkerGlobalScope::executeAnimationFrameCallbacks(double highResTimeMs)
 {
     TemporaryChange<bool> temporaryChange(m_executingAnimationFrameCallbacks, true);
     m_callbackCollection.executeCallbacks(highResTimeMs, highResTimeMs);
     return !m_callbackCollection.isEmpty();
 }
 
 CompositorWorkerThread* CompositorWorkerGlobalScope::thread() const
 {
     return static_cast<CompositorWorkerThread*>(WorkerGlobalScope::thread());
 }
 
 } // namespace blink