Add more missing closing namespace comments.

third_party/WebKit/Source/platform/PlatformInstrumentation.cpp

 /*
  * Copyright (C) 2012 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 26 matching lines @@
 const char PlatformInstrumentation::ImageDecodeEvent[] = "Decode Image";
 const char PlatformInstrumentation::ImageResizeEvent[] = "Resize Image";
 const char PlatformInstrumentation::DrawLazyPixelRefEvent[] = "Draw LazyPixelRef";
 const char PlatformInstrumentation::DecodeLazyPixelRefEvent[] = "Decode LazyPixelRef";
 
 const char PlatformInstrumentation::LazyPixelRef[] = "LazyPixelRef";
 
 const char PlatformInstrumentation::ImageTypeArgument[] = "imageType";
 const char PlatformInstrumentation::CachedArgument[] = "cached";
 
-}
+} // namespace blink