blink: Cleanup core class forward declarations

third_party/WebKit/Source/core/frame/UseCounter.h

 /*
  * 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 23 matching lines @@
 #include "wtf/text/WTFString.h"
 #include <v8.h>
 
 namespace blink {
 
 class CSSStyleSheet;
 class Document;
 class EnumerationHistogram;
 class ExecutionContext;
 class Frame;
-class LocalFrame;
 class StyleSheetContents;
 
 // UseCounter is used for counting the number of times features of
 // Blink are used on real web pages and help us know commonly
 // features are used and thus when it's safe to remove or change them.
 //
 // The Chromium Content layer controls what is done with this data.
 //
 // For instance, in Google Chrome, these counts are submitted anonymously
 // through the UMA histogram recording system in Chrome for users who have the
@@ skipping 1414 matching lines @@
     // Tracks what features/properties need to be reported to the legacy
     // histograms.
     BitVector m_featureBits;
     BitVector m_CSSBits;
   } m_legacyCounter;
 };
 
 }  // namespace blink
 
 #endif  // UseCounter_h