Makes RenderFrameObserver/RenderViewObserver::OnDestruct pure virtual.

content/renderer/speech_recognition_dispatcher.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_RENDERER_SPEECH_RECOGNITION_DISPATCHER_H_
 #define CONTENT_RENDERER_SPEECH_RECOGNITION_DISPATCHER_H_
 
 #include <map>
 #include <memory>
 
@@ skipping 27 matching lines @@
  public:
   explicit SpeechRecognitionDispatcher(RenderViewImpl* render_view);
   ~SpeechRecognitionDispatcher() override;
 
   // Aborts all speech recognitions.
   void AbortAllRecognitions();
 
  private:
   // RenderViewObserver implementation.
   bool OnMessageReceived(const IPC::Message& message) override;
+  void OnDestruct() override;
 
   // blink::WebSpeechRecognizer implementation.
   void start(const blink::WebSpeechRecognitionHandle&,
              const blink::WebSpeechRecognitionParams&,
              blink::WebSpeechRecognizerClient*) override;
   void stop(const blink::WebSpeechRecognitionHandle&,
             blink::WebSpeechRecognizerClient*) override;
   void abort(const blink::WebSpeechRecognitionHandle&,
              blink::WebSpeechRecognizerClient*) override;
 
@@ skipping 32 matching lines @@
   typedef std::map<int, blink::WebSpeechRecognitionHandle> HandleMap;
   HandleMap handle_map_;
   int next_id_;
 
   DISALLOW_COPY_AND_ASSIGN(SpeechRecognitionDispatcher);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_SPEECH_RECOGNITION_DISPATCHER_H_