components: Cleanup class/struct fwd declarations

components/translate/content/renderer/translate_helper.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef COMPONENTS_TRANSLATE_CONTENT_RENDERER_TRANSLATE_HELPER_H_
 #define COMPONENTS_TRANSLATE_CONTENT_RENDERER_TRANSLATE_HELPER_H_
 
 #include <memory>
 #include <string>
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/strings/string16.h"
 #include "base/time/time.h"
 #include "components/translate/content/common/translate.mojom.h"
 #include "components/translate/core/common/translate_errors.h"
 #include "content/public/renderer/render_frame_observer.h"
 #include "mojo/public/cpp/bindings/binding.h"
 #include "url/gurl.h"
 
 namespace blink {
-class WebDocument;
 class WebLocalFrame;
 }
 
 namespace translate {
 
 // This class deals with page translation.
 // There is one TranslateHelper per RenderView.
 class TranslateHelper : public content::RenderFrameObserver,
                         public mojom::Page {
  public:
@@ skipping 125 matching lines @@
 
   // Method factory used to make calls to TranslatePageImpl.
   base::WeakPtrFactory<TranslateHelper> weak_method_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(TranslateHelper);
 };
 
 }  // namespace translate
 
 #endif  // COMPONENTS_TRANSLATE_CONTENT_RENDERER_TRANSLATE_HELPER_H_