Clean up forward declarations in Source/core/editing

Source/core/editing/InputMethodController.h

 /*
  * Copyright (C) 2006, 2007, 2008 Apple 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 15 matching lines @@
 #ifndef InputMethodController_h
 #define InputMethodController_h
 
 #include "core/editing/CompositionUnderline.h"
 #include "core/editing/PlainTextRange.h"
 #include "wtf/Vector.h"
 
 namespace blink {
 
 class Editor;
-class EditorClient;
 class LocalFrame;
 class Range;
 class Text;
 
 class InputMethodController {
     WTF_MAKE_NONCOPYABLE(InputMethodController);
 public:
     enum ConfirmCompositionBehavior {
         DoNotKeepSelection,
         KeepSelection,
@@ skipping 62 matching lines @@
     void selectComposition() const;
     enum FinishCompositionMode { ConfirmComposition, CancelComposition };
     // Returns true if composition exists.
     bool finishComposition(const String&, FinishCompositionMode);
     bool setSelectionOffsets(const PlainTextRange&);
 };
 
 } // namespace blink
 
 #endif // InputMethodController_h