Clean up forward declarations in Source/web

Source/web/WebTextCheckingCompletionImpl.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:
  *
  *     * 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 20 matching lines @@
 #ifndef WebTextCheckingCompletionImpl_h
 #define WebTextCheckingCompletionImpl_h
 
 #include "platform/heap/Handle.h"
 #include "platform/text/TextChecking.h"
 #include "public/web/WebTextCheckingCompletion.h"
 #include "wtf/RefPtr.h"
 
 namespace blink {
 
-class EditorClientImpl;
-
 class WebTextCheckingCompletionImpl final : public WebTextCheckingCompletion {
 public:
     explicit WebTextCheckingCompletionImpl(PassRefPtrWillBeRawPtr<TextCheckingRequest> request)
         : m_request(request)
     {
     }
 
     virtual void didFinishCheckingText(const WebVector<WebTextCheckingResult>&) override;
     virtual void didCancelCheckingText() override;
 
 private:
     virtual ~WebTextCheckingCompletionImpl() { }
 
     RefPtrWillBePersistent<TextCheckingRequest> m_request;
 };
 
 } // namespace blink
 
 #endif