[compositorworker] Register compositor proxies with proxy client

third_party/WebKit/Source/web/CompositorProxyClientImpl.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 CompositorProxyClientImpl_h
 #define CompositorProxyClientImpl_h
 
 #include "core/dom/CompositorProxyClient.h"
+#include "platform/heap/Handle.h"
 #include "wtf/Noncopyable.h"
 
 namespace blink {
 
 class CompositorMutatorImpl;
 class CompositorWorkerGlobalScope;
 class WorkerGlobalScope;
 
 // Mediates between one CompositorWorkerGlobalScope and the associated CompositorMutatorImpl.
 // There is one CompositorProxyClientImpl per worker but there may be multiple for a given
 // mutator, e.g. if a single document creates multiple CompositorWorker objects.
 //
 // Should be accessed only on the compositor thread.
 class CompositorProxyClientImpl final : public GarbageCollected<CompositorProxyClientImpl>, public CompositorProxyClient {
     USING_GARBAGE_COLLECTED_MIXIN(CompositorProxyClientImpl);
     WTF_MAKE_NONCOPYABLE(CompositorProxyClientImpl);
 public:
     CompositorProxyClientImpl(CompositorMutatorImpl*);
     DECLARE_VIRTUAL_TRACE();
 
     // Runs the animation frame callback for the frame starting at the given time.
     // Returns true if another animation frame was requested (i.e. should be reinvoked next frame).
     bool mutate(double monotonicTimeNow);
 
     // CompositorProxyClient:
     void setGlobalScope(WorkerGlobalScope*) override;
     void requestAnimationFrame() override;
+    void registerCompositorProxy(CompositorProxy*) override;
+    void unregisterCompositorProxy(CompositorProxy*) override;
 
 private:
     bool executeAnimationFrameCallbacks(double monotonicTimeNow);
 
     Member<CompositorMutatorImpl> m_mutator;
 
     Member<CompositorWorkerGlobalScope> m_globalScope;
     bool m_requestedAnimationFrameCallbacks;
+
+    typedef HeapHashSet<WeakMember<CompositorProxy>> ProxySet;
+    typedef HeapHashMap<uint64_t, Member<ProxySet>> ProxyMap;

[jbroman, 2016/06/10 19:29:34]

One thing to watch out for here: if the last object to die here dies without
being explicitly disconnected, the set will become empty but the entry won't be
removed from the map. That may cause memory to increase over time.

(But I don't know what the ideal way to handle this from an Oilpan standpoint
is; haraken can probably offer advice.)

+    ProxyMap m_proxyMap;
 };
 
 } // namespace blink
 
 #endif // CompositorProxyClientImpl_h