chrome: Cleanup class/struct forward declarations

chrome/browser/ui/webui/translate_internals/translate_internals_handler.h

 // Copyright 2013 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 CHROME_BROWSER_UI_WEBUI_TRANSLATE_INTERNALS_TRANSLATE_INTERNALS_HANDLER_H_
 #define CHROME_BROWSER_UI_WEBUI_TRANSLATE_INTERNALS_TRANSLATE_INTERNALS_HANDLER_H_
 
 #include <memory>
 #include <string>
 
 #include "base/callback_list.h"
 #include "base/macros.h"
 #include "components/translate/core/browser/translate_language_list.h"
 #include "components/translate/core/browser/translate_manager.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "content/public/browser/web_ui_message_handler.h"
 #include "content/public/common/webplugininfo.h"
 
 namespace translate {
-struct LanguageDetectionDetails;
 struct TranslateErrorDetails;
 struct TranslateEventDetails;
 }
 
 namespace base {
-class DictionaryValue;
 class ListValue;
 class Value;
 }
 
 namespace content {
 class NotificationDetails;
 class NotificationSource;
 }
 
 // The handler class for TranslateInternals page operations.
@@ skipping 55 matching lines @@
   std::unique_ptr<
       translate::TranslateManager::TranslateErrorCallbackList::Subscription>
       error_subscription_;
 
   content::NotificationRegistrar notification_registrar_;
 
   DISALLOW_COPY_AND_ASSIGN(TranslateInternalsHandler);
 };
 
 #endif  // CHROME_BROWSER_UI_WEBUI_TRANSLATE_INTERNALS_TRANSLATE_INTERNALS_HANDLER_H_