RefCounted types should not have public destructors, content/ remaining bits

content/public/browser/speech_recognizer.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_RECOGNIZER_H_
 #define CONTENT_PUBLIC_BROWSER_SPEECH_RECOGNIZER_H_
 #pragma once
 
 #include <string>
 
 #include "base/memory/ref_counted.h"
 #include "content/common/content_export.h"
 
 namespace net {
 class URLRequestContextGetter;
 }
 
 namespace content {
 
 class SpeechRecognitionEventListener;
 
 // Records audio, sends recorded audio to server and translates server response
 // to recognition result.
 // TODO(primiano) remove this public interface as soon as we fix speech input
 // extensions.
 class SpeechRecognizer : public base::RefCountedThreadSafe<SpeechRecognizer> {
  public:
-
   CONTENT_EXPORT static SpeechRecognizer* Create(
       SpeechRecognitionEventListener* event_listener,
       int session_id,
       const std::string& language,
       const std::string& grammar,
       net::URLRequestContextGetter* context_getter,
       bool filter_profanities,
       const std::string& hardware_info,
       const std::string& origin_url);
 
-  virtual ~SpeechRecognizer() {}
-
   // Starts audio recording and the recognition process. The same
   // SpeechRecognizer instance can be used multiple times for speech recognition
   // though each recognition request can be made only after the previous one
   // completes (i.e. after receiving
   // SpeechRecognitionEventListener::OnRecognitionEnd).
   virtual void StartRecognition() = 0;
 
   // Stops recording audio and cancels recognition. Any audio recorded so far
   // gets discarded.
   virtual void AbortRecognition() = 0;
 
   // Stops recording audio and finalizes recognition, possibly getting results.
   virtual void StopAudioCapture() = 0;
 
   // Checks wether the recognizer is active, that is, either capturing audio
   // or waiting for a result.
   virtual bool IsActive() const = 0;
 
-  // Checks wether the recognizer is capturing audio.
+  // Checks whether the recognizer is capturing audio.
   virtual bool IsCapturingAudio() const = 0;
+
+ protected:
+  friend class base::RefCountedThreadSafe<SpeechRecognizer>;
+  virtual ~SpeechRecognizer() {}
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_SPEECH_RECOGNIZER_H_