Invalidate the weak factory in SpeechRecognizer::EventListener::StopOnIOThread().

chrome/browser/ui/app_list/speech_recognizer.cc

 // Copyright 2014 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.
 
 #include "chrome/browser/ui/app_list/speech_recognizer.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/strings/string16.h"
@@ skipping 137 matching lines @@
   DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
   if (session_ == kInvalidSessionId)
     return;
 
   // Prevent recursion.
   int session = session_;
   session_ = kInvalidSessionId;
   StopSpeechTimeout();
   content::SpeechRecognitionManager::GetInstance()->StopAudioCaptureForSession(
       session);
+  weak_factory_.InvalidateWeakPtrs();
 }
 
 void SpeechRecognizer::EventListener::NotifyRecognitionStateChanged(
     SpeechRecognitionState new_state) {
   content::BrowserThread::PostTask(
       content::BrowserThread::UI,
       FROM_HERE,
       base::Bind(&SpeechRecognizerDelegate::OnSpeechRecognitionStateChanged,
                  delegate_,
                  new_state));
@@ skipping 139 matching lines @@
 void SpeechRecognizer::Stop() {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
   content::BrowserThread::PostTask(
       content::BrowserThread::IO,
       FROM_HERE,
       base::Bind(&SpeechRecognizer::EventListener::StopOnIOThread,
                  speech_event_listener_));
 }
 
 }  // namespace app_list