content: Cleanup class/struct forward declarations

content/public/browser/speech_recognition_manager_delegate.h

 // Copyright (c) 2012 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 CONTENT_PUBLIC_BROWSER_SPEECH_RECOGNITION_MANAGER_DELEGATE_H_
 #define CONTENT_PUBLIC_BROWSER_SPEECH_RECOGNITION_MANAGER_DELEGATE_H_
 
 #include <string>
 
 #include "base/callback_forward.h"
 #include "content/public/common/speech_recognition_error.h"
 
 namespace content {
 
 class SpeechRecognitionEventListener;
-struct SpeechRecognitionResult;
 
 // Allows embedders to display the current state of recognition, for getting the
 // user's permission and for fetching optional request information.
 class SpeechRecognitionManagerDelegate {
  public:
   virtual ~SpeechRecognitionManagerDelegate() {}
 
   // Checks (asynchronously) if current setup allows speech recognition.
   // This is called on the IO thread.
   virtual void CheckRecognitionIsAllowed(
       int session_id,
       base::Callback<void(bool ask_user, bool is_allowed)> callback) = 0;
 
   // Checks whether the delegate is interested (returning a non nullptr ptr) or
   // not (returning nullptr) in receiving a copy of all sessions events.
   // This is called on the IO thread.
   virtual SpeechRecognitionEventListener* GetEventListener() = 0;
 
   // Checks whether the speech recognition for the given renderer should filter
   // profanities or not.
   virtual bool FilterProfanities(int render_process_id) = 0;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_SPEECH_RECOGNITION_MANAGER_DELEGATE_H_