Avoid exposing cc::Layer tree to CompositorProxy

third_party/WebKit/Source/web/CompositorMutatorImpl.h

Index: third_party/WebKit/Source/web/CompositorMutatorImpl.h
diff --git a/third_party/WebKit/Source/web/CompositorMutatorImpl.h b/third_party/WebKit/Source/web/CompositorMutatorImpl.h
index f8d13118a455df0b62bd72fc5d10d4d91329d6f2..65cedd7e4c234d52b6f19334b6cb53055b963266 100644
--- a/third_party/WebKit/Source/web/CompositorMutatorImpl.h
+++ b/third_party/WebKit/Source/web/CompositorMutatorImpl.h
@@ -16,6 +16,7 @@ namespace blink {
 
 class CompositorAnimator;
 class CompositorMutatorClient;
+class CompositorProxy;
 
 // Fans out requests from the compositor to all of the registered
 // CompositorAnimators which can then mutate layers through their respective
@@ -38,6 +39,9 @@ class CompositorMutatorImpl final : public CompositorMutator {
   void registerCompositorAnimator(CompositorAnimator*);
   void unregisterCompositorAnimator(CompositorAnimator*);
 
+  void registerCompositorProxy(const CompositorProxy*);
+  void unregisterCompositorProxy(const CompositorProxy*);
+
   void setNeedsMutate();
 
   void setClient(CompositorMutatorClient* client) { m_client = client; }