Add flow control between renderer and GPU processes, and, on Mac OS X,...

chrome/browser/renderer_host/render_widget_host_view_mac.h

Index: chrome/browser/renderer_host/render_widget_host_view_mac.h
===================================================================
--- chrome/browser/renderer_host/render_widget_host_view_mac.h	(revision 67289)
+++ chrome/browser/renderer_host/render_widget_host_view_mac.h	(working copy)
@@ -243,8 +243,12 @@
       int32 width,
       int32 height,
       TransportDIB::Handle transport_dib);
-  virtual void AcceleratedSurfaceBuffersSwapped(gfx::PluginWindowHandle window,
-                                                uint64 surface_id);
+  virtual void AcceleratedSurfaceBuffersSwapped(
+      gfx::PluginWindowHandle window,
+      uint64 surface_id,
+      int32 renderer_id,
+      int32 route_id,
+      uint64 swap_buffers_count);
   virtual void GpuRenderingStateDidChange();
   void DrawAcceleratedSurfaceInstance(
       CGLContextObj context,
@@ -273,6 +277,12 @@
   // should be called after the software backing store has been painted to.
   void HandleDelayedGpuViewHiding();
 
+  // This is called from the display link thread, and provides the GPU
+  // process a notion of how quickly the browser is able to keep up with it.
+  void AcknowledgeSwapBuffers(int renderer_id,
+                              int32 route_id,
+                              uint64 swap_buffers_count);
+
   // These member variables should be private, but the associated ObjC class
   // needs access to them and can't be made a friend.