ui: Cleanup class/struct forward declarations

blimp/client/core/compositor/blimp_compositor.h

Index: blimp/client/core/compositor/blimp_compositor.h
diff --git a/blimp/client/core/compositor/blimp_compositor.h b/blimp/client/core/compositor/blimp_compositor.h
index 974f4a291853f5bbf79bb64dc29e6292e6f06dcb..0724e3986a0eb6358c85e16b362355adcc7ec243 100644
--- a/blimp/client/core/compositor/blimp_compositor.h
+++ b/blimp/client/core/compositor/blimp_compositor.h
@@ -28,6 +28,7 @@ class Thread;
 }  // namespace base
 
 namespace cc {
+class AnimationHost;
 class InputHandler;
 
 namespace proto {
@@ -149,6 +150,8 @@ class BlimpCompositor : public cc::LayerTreeHostClient,
   void Initialize();
   virtual std::unique_ptr<cc::LayerTreeHostInProcess> CreateLayerTreeHost();
 
+  cc::AnimationHost* animation_host() { return animation_host_.get(); }
+
  private:
   class FrameTrackingSwapPromise;
 
@@ -212,12 +215,12 @@ class BlimpCompositor : public cc::LayerTreeHostClient,
 
   cc::FrameSinkId frame_sink_id_;
 
+  std::unique_ptr<cc::AnimationHost> animation_host_;
   std::unique_ptr<cc::LayerTreeHostInProcess> host_;
 
-  // The SurfaceFactory is bound to the lifetime of the |proxy_client_|. When
-  // detached, the surface factory will be destroyed.
   std::unique_ptr<cc::SurfaceFactory> surface_factory_;
   base::WeakPtr<BlimpCompositorFrameSinkProxyClient> proxy_client_;
+  bool bound_to_proxy_;
 
   // Whether or not |host_| has asked for a new CompositorFrameSink.
   bool compositor_frame_sink_request_pending_;