Partial swaps on OSX

content/browser/renderer_host/accelerated_surface_container_mac.h

Index: content/browser/renderer_host/accelerated_surface_container_mac.h
diff --git a/content/browser/renderer_host/accelerated_surface_container_mac.h b/content/browser/renderer_host/accelerated_surface_container_mac.h
index c46430fc6064801fcc8d0a1024719f7e7bcd9dae..1bbf7308888f58e3772828188a90068af523c54c 100644
--- a/content/browser/renderer_host/accelerated_surface_container_mac.h
+++ b/content/browser/renderer_host/accelerated_surface_container_mac.h
@@ -83,10 +83,17 @@ class AcceleratedSurfaceContainerMac {
 
   // Notifies the the container that its surface was painted to.
   void set_was_painted_to(uint64 surface_id);
+  void set_was_painted_to(uint64 surface_id,
+                          const gfx::Rect& update_rect);
 
   // Notifies the container that its surface is invalid.
   void set_surface_invalid() { was_painted_to_ = false; }
  private:
+  // Enqueue our texture for later deletion.
+  void EnqueueTextureForDeletion();
+
+  void set_was_painted_to_common(uint64 surface_id);
+
   // The manager of this accelerated surface container.
   AcceleratedSurfaceContainerManagerMac* manager_;
 
@@ -129,6 +136,10 @@ class AcceleratedSurfaceContainerMac {
   // True if we need to upload the texture again during the next draw.
   bool texture_needs_upload_;
 
+  // The region that was updated via a partial update. |update_rect_.IsEmpty()|
+  // indicates that the whole region was updated.
+  gfx::Rect update_rect_;
+
   // This may refer to an old version of the texture if the container is
   // resized, for example.
   GLuint texture_pending_deletion_;
@@ -140,12 +151,6 @@ class AcceleratedSurfaceContainerMac {
   // it before it hasn't been painted to at least once.
   bool was_painted_to_;
 
-  // Releases the IOSurface reference, if any, retained by this object.
-  void ReleaseIOSurface();
-
-  // Enqueue our texture for later deletion.
-  void EnqueueTextureForDeletion();
-
   DISALLOW_COPY_AND_ASSIGN(AcceleratedSurfaceContainerMac);
 };