Adding status to swap complete

ui/gfx/swap_result.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "ui/gfx/screen.h"
-
-#include "base/logging.h"
+#ifndef UI_GFX_SWAP_RESULT_H_
+#define UI_GFX_SWAP_RESULT_H_
 
 namespace gfx {
 
-Screen* CreateNativeScreen() {
-  NOTREACHED() << "Implementation should be installed at higher level.";
-  return NULL;
-}
+enum SwapResult {
+  SwapAck,
+  SwapFailed,
+  SwapNakRecreateBuffers,
+  SWAP_RESULT_LAST,
+};
 
 }  // namespace gfx
+
+#endif  // UI_GFX_SWAP_RESULT_H_