Re-land: Mark async texture uploads as completed from the upload thread.

ui/gl/async_pixel_transfer_delegate.h

Index: ui/gl/async_pixel_transfer_delegate.h
diff --git a/ui/gl/async_pixel_transfer_delegate.h b/ui/gl/async_pixel_transfer_delegate.h
index d07a77da88ec895ff3e41a2bf75c7cad45b53513..da457225ecdcaebb34eeb4e9de856a14c9c0f5a4 100644
--- a/ui/gl/async_pixel_transfer_delegate.h
+++ b/ui/gl/async_pixel_transfer_delegate.h
@@ -78,6 +78,8 @@ class GL_EXPORT AsyncPixelTransferState :
 
 class GL_EXPORT AsyncPixelTransferDelegate {
  public:
+  typedef base::Callback<void(const AsyncMemoryParams&)> CompletionCallback;
+
   static scoped_ptr<AsyncPixelTransferDelegate>
       Create(gfx::GLContext* context);
   virtual ~AsyncPixelTransferDelegate() {}
@@ -89,8 +91,10 @@ class GL_EXPORT AsyncPixelTransferDelegate {
     return make_scoped_ptr(CreateRawPixelTransferState(texture_id));
   }
 
+  // There's no guarantee that callback will run on the caller thread.
   virtual void AsyncNotifyCompletion(
-      const base::Closure& notify_task) = 0;
+      const AsyncMemoryParams& mem_params,
+      const CompletionCallback& callback) = 0;
 
   virtual void AsyncTexImage2D(
       AsyncPixelTransferState* state,