Fix assorted issues with remote CoreAnimation

content/common/gpu/image_transport_surface_calayer_mac.h

Index: content/common/gpu/image_transport_surface_calayer_mac.h
diff --git a/content/common/gpu/image_transport_surface_calayer_mac.h b/content/common/gpu/image_transport_surface_calayer_mac.h
index 85ee4181a3a33c82e46c6c9b4a825cdd5a36817c..dbea6ae947710f145f3ebdc3482eaa8f328ee561 100644
--- a/content/common/gpu/image_transport_surface_calayer_mac.h
+++ b/content/common/gpu/image_transport_surface_calayer_mac.h
@@ -28,18 +28,26 @@ class CALayerStorageProvider
       CGLContextObj context, GLuint texture,
       gfx::Size pixel_size, float scale_factor) OVERRIDE;
   virtual void FreeColorBufferStorage() OVERRIDE;
-  virtual uint64 GetSurfaceHandle() const OVERRIDE;
-  virtual void WillSwapBuffers() OVERRIDE;
+  virtual void DiscardBackbuffer() OVERRIDE;
+  virtual uint64 SwapBuffersAndGetSurfaceHandle() OVERRIDE;
   virtual void CanFreeSwappedBuffer() OVERRIDE;
 
   // Interface to ImageTransportLayer:
   CGLContextObj LayerShareGroupContext();
   bool LayerCanDraw();
   void LayerDoDraw();
+  void LayerResetStorageProvider();
 
  private:
+  void DisplayTimeoutFired();
+  void UnblockIfNeededAfterPendingFrameDrawn();
+
   ImageTransportSurfaceFBO* transport_surface_;
 
+  // Used to determine if we should use setNeedsDisplay or setAsynchronous to
+  // animate.
+  const bool gpu_vsync_disabled_;
+
   // Set when a new swap occurs, and un-set when |layer_| draws that frame.
   bool has_pending_draw_;
 
@@ -53,11 +61,19 @@ class CALayerStorageProvider
   base::ScopedTypeRef<CGLContextObj> share_group_context_;
   GLuint fbo_texture_;
   gfx::Size fbo_pixel_size_;
+  float fbo_scale_factor_;
 
   // The CALayer that the current frame is being drawn into.
   base::scoped_nsobject<CAContext> context_;
   base::scoped_nsobject<ImageTransportLayer> layer_;
 
+  // CoreAnimation places back-pressure on the browser compositor (which then
+  // places back-pressure on the renderer) by by descheduling the command buffer
+  // until CoreAnimation tells us it's time to draw. Sometimes this callback is
+  // simply skipped, which can lead to hangs. Prevent hangs by always
+  // acknowledging the frame after timeout of 1/6th of a second has passed.
+  base::DelayTimer<CALayerStorageProvider> display_timeout_timer_;
+
   DISALLOW_COPY_AND_ASSIGN(CALayerStorageProvider);
 };