Clean up forward declarations in Source/core/inspector

Source/core/inspector/InspectorCSSAgent.h

 /*
  * Copyright (C) 2010, 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 24 matching lines @@
 #include "wtf/HashCountedSet.h"
 #include "wtf/HashMap.h"
 #include "wtf/HashSet.h"
 #include "wtf/PassRefPtr.h"
 #include "wtf/RefPtr.h"
 #include "wtf/Vector.h"
 #include "wtf/text/WTFString.h"
 
 namespace blink {
 
-struct CSSParserString;
 class CSSRule;
 class CSSRuleList;
 class CSSStyleRule;
 class CSSStyleSheet;
 class Document;
 class Element;
 class InspectorFrontend;
 class InspectorResourceAgent;
-class InstrumentingAgents;
 class MediaList;
 class Node;
-class PlatformFontUsage;
 class RenderText;
-class StyleResolver;
 
 class InspectorCSSAgent final
     : public InspectorBaseAgent<InspectorCSSAgent>
     , public InspectorDOMAgent::DOMListener
     , public InspectorBackendDispatcher::CSSCommandHandler
     , public InspectorStyleSheetBase::Listener {
     WTF_MAKE_NONCOPYABLE(InspectorCSSAgent);
     WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(InspectorCSSAgent);
 public:
     enum MediaListSource {
@@ skipping 149 matching lines @@
     bool m_isSettingStyleSheetText;
 
     friend class InspectorResourceContentLoaderCallback;
     friend class StyleSheetBinder;
 };
 
 
 } // namespace blink
 
 #endif // !defined(InspectorCSSAgent_h)