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

third_party/WebKit/Source/web/CompositorMutatorImpl.h

+// Copyright 2016 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 CompositorMutatorImpl_h
+#define CompositorMutatorImpl_h
+
+#include "platform/graphics/CompositorMutator.h"
+#include "platform/heap/Handle.h"
+#include "platform/heap/HeapAllocator.h"
+#include "wtf/Noncopyable.h"
+#include "wtf/OwnPtr.h"
+#include "wtf/PassOwnPtr.h"
+
+namespace blink {
+
+class CompositorProxy;
+class CompositorProxyClientImpl;
+class CompositorWorkerGlobalScope;
+class CompositorMutatorClient;
+class CustomCompositorAnimationManager;
+class WaitableEvent;
+
+class CompositorMutatorImpl final : public CompositorMutator {

[jbroman, 2016/04/29 19:42:22]

Class comment, please. Maybe something along the lines of:

// Fans out requests from the compositor to the various registered clients
// which can mutate layers (e.g., one per compositor worker).
//
// Should be accessed only on the compositor thread.

[flackr, 2016/05/03 22:24:54]

Done.

+    WTF_MAKE_NONCOPYABLE(CompositorMutatorImpl);
+
+public:
+    static CompositorMutatorImpl* create();
+    ~CompositorMutatorImpl() override;
+
+    DEFINE_INLINE_TRACE()
+    {
+        CompositorMutator::trace(visitor);
+        visitor->trace(m_proxyClients);
+    }
+
+    // CompositorMutator implementation.
+    bool mutate(double monotonicTimeNow) override;
+
+    void registerProxyClient(CompositorProxyClientImpl*);
+    void unregisterProxyClient(CompositorProxyClientImpl*);
+
+    void setNeedsMutate();
+
+    void setClient(CompositorMutatorClient* client) { m_client = client; }
+    CustomCompositorAnimationManager* animationManager() { return m_animationManager.get(); }
+
+private:
+    CompositorMutatorImpl();
+
+    using ProxyClients = HeapHashSet<WeakMember<CompositorProxyClientImpl>>;
+    ProxyClients m_proxyClients;
+
+    OwnPtr<CustomCompositorAnimationManager> m_animationManager;
+    CompositorMutatorClient* m_client;
+};
+
+} // namespace blink
+
+#endif // CompositorMutatorImpl_h