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 ffa70007255efadc0c9c64f2b064173355341f25..486e9d67dfa4c6f9ab8026eceb3e4554a80c315b 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
@@ -39,6 +40,9 @@ 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) { client_ = client; }