compositor-worker: Create a separate CompositorWorkerGlobalScope for compositor workers.

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.
+
+#include "core/workers/DedicatedWorkerGlobalScope.h"
+
+#ifndef CompositorWorkerGlobalScope_h
+#define CompositorWorkerGlobalScope_h
+
+namespace blink {
+
+class CompositorWorkerThread;
+class RequestAnimationFrameCallback;
+
+class CompositorWorkerGlobalScope final : public DedicatedWorkerGlobalScope {
+    DEFINE_WRAPPERTYPEINFO();
+public:
+    static PassRefPtrWillBeRawPtr<CompositorWorkerGlobalScope> create(CompositorWorkerThread*, PassOwnPtrWillBeRawPtr<WorkerThreadStartupData>, double timeOrigin);
+    virtual ~CompositorWorkerGlobalScope();
+
+    // EventTarget
+    const AtomicString& interfaceName() const override;
+
+    int requestCompositorFrame(RequestAnimationFrameCallback*);
+    void cancelCompositorFrame(int id);
+
+    void executeCompositorFrameCallbacks(double monotonicTimeNow);
+
+    DECLARE_VIRTUAL_TRACE();
+
+protected:
+    CompositorWorkerGlobalScope(const KURL&, const String& userAgent, CompositorWorkerThread*, double timeOrigin, const SecurityOrigin*, PassOwnPtrWillBeRawPtr<WorkerClients>);
+
+private:
+    typedef PersistentHeapVectorWillBeHeapVector<Member<RequestAnimationFrameCallback>> CallbackList;
+    CallbackList m_callbacks;
+    CallbackList m_callbacksToInvoke; // only non-empty while inside executeCallbacks
+
+    int m_nextCallbackId;
+};
+
+} // namespace blink
+
+#endif // CompositorWorkerGlobalScope_h