Cleanup namespace usage in platform/graphics/[G-S]*

Source/platform/graphics/GraphicsContextRecorder.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 131 matching lines @@
     return timings.release();
 }
 
 PassRefPtr<JSONArray> GraphicsContextSnapshot::snapshotCommandLog() const
 {
     LoggingCanvas canvas(m_picture->width(), m_picture->height());
     m_picture->draw(&canvas);
     return canvas.log();
 }
 
-}
+} // namespace blink