Very basic Android browser-side compositing support.

content/browser/renderer_host/render_view_host_impl.h

Index: content/browser/renderer_host/render_view_host_impl.h
diff --git a/content/browser/renderer_host/render_view_host_impl.h b/content/browser/renderer_host/render_view_host_impl.h
index 940ba020bf39ae745fac7520c62af023fa3a9167..15b3f3f56e2458831eb9d1a5c94ee71a894c2c06 100644
--- a/content/browser/renderer_host/render_view_host_impl.h
+++ b/content/browser/renderer_host/render_view_host_impl.h
@@ -366,6 +366,14 @@ class CONTENT_EXPORT RenderViewHostImpl
       const NativeWebKeyboardEvent& key_event) OVERRIDE;
   virtual gfx::Rect GetRootWindowResizerRect() const OVERRIDE;
 
+#if defined(OS_ANDROID)
+  virtual void AttachLayer(WebKit::WebLayer* layer) OVERRIDE;
+  virtual void RemoveLayer(WebKit::WebLayer* layer) OVERRIDE;
+
+  void DidSelectPopupMenuItems(const std::vector<int>& selected_indices);
+  void DidCancelPopupMenu();

[jam, 2012/09/04 16:44:48]

nit: you have this twice now.. also, I think it's better to keep one ifdef right
beside the interface for the overridden methods, and another below for other
android-only methods. 

+#endif
+
   // Creates a new RenderView with the given route id.
   void CreateNewWindow(
       int route_id,
@@ -385,11 +393,6 @@ class CONTENT_EXPORT RenderViewHostImpl
   void DidCancelPopupMenu();
 #endif
 
-#if defined(OS_ANDROID)
-  void DidSelectPopupMenuItems(const std::vector<int>& selected_indices);
-  void DidCancelPopupMenu();
-#endif
-
   // User rotated the screen. Calls the "onorientationchange" Javascript hook.
   void SendOrientationChangeEvent(int orientation);