cc: Fix readback from non-root layers.

cc/output/gl_renderer.h

Index: cc/output/gl_renderer.h
diff --git a/cc/output/gl_renderer.h b/cc/output/gl_renderer.h
index 17bd8b5e7a5bb82cddeb4ddb8d0c31f9ae94ba28..c83169dfc6acd3b2b4925c7ce0a9bbd476613f3f 100644
--- a/cc/output/gl_renderer.h
+++ b/cc/output/gl_renderer.h
@@ -92,6 +92,7 @@ class CC_EXPORT GLRenderer
   }
 
   void GetFramebufferPixelsAsync(gfx::Rect rect,
+                                 bool flipped_y,
                                  CopyRenderPassCallback callback);
   bool GetFramebufferTexture(ScopedResource* resource, gfx::Rect device_rect);
   void ReleaseRenderPassTextures();
@@ -191,12 +192,14 @@ class CC_EXPORT GLRenderer
   void DoGetFramebufferPixels(
       uint8* pixels,
       gfx::Rect rect,
+      bool flipped_y,
       const AsyncGetFramebufferPixelsCleanupCallback& cleanup_callback);
   void FinishedReadback(
       const AsyncGetFramebufferPixelsCleanupCallback& cleanup_callback,
       unsigned source_buffer,
       uint8_t* dest_pixels,
-      gfx::Size size);
+      gfx::Size size,
+      bool flipped_y);
   void PassOnSkBitmap(
       scoped_ptr<SkBitmap> bitmap,
       scoped_ptr<SkAutoLockPixels> lock,
@@ -407,6 +410,7 @@ class CC_EXPORT GLRenderer
   ScopedPtrVector<PendingAsyncReadPixels> pending_async_read_pixels_;
 
   scoped_ptr<ResourceProvider::ScopedWriteLockGL> current_framebuffer_lock_;
+  gfx::Size current_framebuffer_size_;
 
   scoped_refptr<ResourceProvider::Fence> last_swap_fence_;