Support copying a partial rectangle region from the compositing surface on Aura and GTK.

content/browser/renderer_host/render_widget_host_view_win.cc

Index: content/browser/renderer_host/render_widget_host_view_win.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_win.cc b/content/browser/renderer_host/render_widget_host_view_win.cc
index 9149c239a8dc25a2187b72008953838d81bb8470..3bdcf057ea05111d50ef9dd4ebeeae8940a3a43e 100644
--- a/content/browser/renderer_host/render_widget_host_view_win.cc
+++ b/content/browser/renderer_host/render_widget_host_view_win.cc
@@ -1196,22 +1196,25 @@ BackingStore* RenderWidgetHostViewWin::AllocBackingStore(
   return new BackingStoreWin(render_widget_host_, size);
 }
 
+// TODO(mazda): Support copying a partial rectangle from the compositing surface
+// with |src_subrect| (http://crbug.com/118571).
 void RenderWidgetHostViewWin::CopyFromCompositingSurface(
-    const gfx::Size& size,
+    const gfx::Rect& /* src_subrect */,
+    const gfx::Size& dst_size,
     const base::Callback<void(bool)>& callback,
     skia::PlatformCanvas* output) {
   base::ScopedClosureRunner scoped_callback_runner(base::Bind(callback, false));
   if (!accelerated_surface_.get())
     return;
 
-  if (size.IsEmpty())
+  if (dst_size.IsEmpty())
     return;
 
-  if (!output->initialize(size.width(), size.height(), true))
+  if (!output->initialize(dst_size.width(), dst_size.height(), true))
     return;
 
   const bool result = accelerated_surface_->CopyTo(
-      size, output->getTopDevice()->accessBitmap(true).getPixels());
+      dst_size, output->getTopDevice()->accessBitmap(true).getPixels());
   scoped_callback_runner.Release();
   callback.Run(result);
 }