Making sure that SpeechRecognitionDispatcherHost is not used after free

content/public/browser/speech_recognition_session_config.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_SESSION_CONFIG_H_
 #define CONTENT_PUBLIC_BROWSER_SPEECH_RECOGNITION_SESSION_CONFIG_H_
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
 #include "content/common/content_export.h"
 #include "content/public/browser/speech_recognition_session_context.h"
 #include "content/public/common/speech_recognition_grammar.h"
 #include "net/url_request/url_request_context_getter.h"
 
 namespace content {
 
 class SpeechRecognitionEventListener;
 
 // Configuration params for creating a new speech recognition session.
 struct CONTENT_EXPORT SpeechRecognitionSessionConfig {
   SpeechRecognitionSessionConfig();
   ~SpeechRecognitionSessionConfig();
 
   bool is_legacy_api;
   std::string language;
   SpeechRecognitionGrammarArray grammars;
   std::string origin_url;
   bool filter_profanities;
   bool continuous;
   bool interim_results;
   uint32 max_hypotheses;
   SpeechRecognitionSessionContext initial_context;
   scoped_refptr<net::URLRequestContextGetter> url_request_context_getter;
-  SpeechRecognitionEventListener* event_listener;
+  base::WeakPtr<SpeechRecognitionEventListener> event_listener;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_SPEECH_RECOGNITION_SESSION_CONFIG_H_