compositor-worker: Allow registering compositor-frame callbacks.

Source/modules/compositorworker/CompositorWorkerGlobalScope.h

 // 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.
 
 #ifndef CompositorWorkerGlobalScope_h
 #define CompositorWorkerGlobalScope_h
 
 #include "core/dom/MessagePort.h"
+#include "core/dom/RequestAnimationFrameCallbackCollection.h"
 #include "core/workers/WorkerGlobalScope.h"
 
 namespace blink {
 
 class CompositorWorkerThread;
 class WorkerThreadStartupData;
 
 class CompositorWorkerGlobalScope final : public WorkerGlobalScope {
     DEFINE_WRAPPERTYPEINFO();
 public:
     static PassRefPtrWillBeRawPtr<CompositorWorkerGlobalScope> create(CompositorWorkerThread*, PassOwnPtrWillBeRawPtr<WorkerThreadStartupData>, double timeOrigin);
     virtual ~CompositorWorkerGlobalScope();
 
     // EventTarget
     const AtomicString& interfaceName() const override;
 
     void postMessage(ExecutionContext*, PassRefPtr<SerializedScriptValue>, const MessagePortArray*, ExceptionState&);
     DEFINE_ATTRIBUTE_EVENT_LISTENER(message);
 
-    void executeCompositorFrameCallbacks(double monotonicTimeNow);
+    int requestCompositorFrame(RequestAnimationFrameCallback*);

[esprehn, 2015/03/30 18:43:12]

Why not just call this thing requestAnimationFrame instead?

[sadrul, 2015/03/31 02:45:36]

Done.

+    void cancelCompositorFrame(int id);
+    void executeCompositorFrameCallbacks(double highResTimeNow);
 
     // ExecutionContext:
     bool isCompositorWorkerGlobalScope() const override { return true; }
 
 private:
     CompositorWorkerGlobalScope(const KURL&, const String& userAgent, CompositorWorkerThread*, double timeOrigin, const SecurityOrigin*, PassOwnPtrWillBeRawPtr<WorkerClients>);
     CompositorWorkerThread* thread() const;
+
+    RequestAnimationFrameCallbackCollection m_callbackCollection;
 };
 
 } // namespace blink
 
 #endif // CompositorWorkerGlobalScope_h