Fixed the speech crash when the render view has gone away then users click "try again"

chrome/browser/speech/chrome_speech_recognition_manager_delegate.cc

Index: chrome/browser/speech/chrome_speech_recognition_manager_delegate.cc
diff --git a/chrome/browser/speech/chrome_speech_recognition_manager_delegate.cc b/chrome/browser/speech/chrome_speech_recognition_manager_delegate.cc
index 05b435dc70b800c62efa2a27dfc7826d6d5d366f..0d6c75fa9ca4aa7d47aeeab0b6c692386fe6a90c 100644
--- a/chrome/browser/speech/chrome_speech_recognition_manager_delegate.cc
+++ b/chrome/browser/speech/chrome_speech_recognition_manager_delegate.cc
@@ -276,7 +276,9 @@ void ChromeSpeechRecognitionManagerDelegate::InfoBubbleFocusChanged(
 }
 
 void ChromeSpeechRecognitionManagerDelegate::RestartLastSession() {

[tommi (sloooow) - chröme, 2013/03/28 10:38:46]

Hmm... rename to MaybeRestartLastSession?

-  DCHECK(last_session_config_.get());
+  if (!last_session_config_.get())
+    return;

[tommi (sloooow) - chröme, 2013/03/28 10:38:46]

what effect does this have on the functionality?
Also, please add a comment for how we can get here.

+
   SpeechRecognitionManager* manager = SpeechRecognitionManager::GetInstance();
   const int new_session_id = manager->CreateSession(*last_session_config_);
   DCHECK_NE(SpeechRecognitionManager::kSessionIDInvalid, new_session_id);
@@ -472,6 +474,13 @@ ChromeSpeechRecognitionManagerDelegate::GetEventListener() {
   return this;
 }
 
+void ChromeSpeechRecognitionManagerDelegate::OnAbortSessionsForListener(
+    SpeechRecognitionEventListener* listener) {

[tommi (sloooow) - chröme, 2013/03/28 10:38:46]

Passing the listener here feels hacky.  I would rather want to have something
like:
OnSessionAborted(int session_id)

Or if there's at most ever only one session active, then no parameter.
In what cases can this function be called and the listener does not match
last_session_config_->event_listener?

+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  if (last_session_config_->event_listener == listener)
+    last_session_config_.reset();
+}
+
 void ChromeSpeechRecognitionManagerDelegate::CheckRenderViewType(
     base::Callback<void(bool ask_user, bool is_allowed)> callback,
     int render_process_id,