Show error messages in speech bubble allowing user to retry as well.

chrome/browser/speech/speech_recognizer.h

 // Copyright (c) 2010 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 CHROME_BROWSER_SPEECH_SPEECH_RECOGNIZER_H_
 #define CHROME_BROWSER_SPEECH_SPEECH_RECOGNIZER_H_
 
 #include <list>
 #include <string>
 #include <utility>
@@ skipping 33 matching lines @@
     // detecting silence in user input or if |StopRecording| was called. The
     // delegate has to wait until |DidCompleteRecognition| is invoked before
     // destroying the |SpeechRecognizer| object.
     virtual void DidCompleteRecording(int caller_id) = 0;
 
     // This is guaranteed to be the last method invoked in the recognition
     // sequence and the |SpeechRecognizer| object can be freed up if necessary.
     virtual void DidCompleteRecognition(int caller_id) = 0;
 
     // Invoked if there was an error while recording or recognizing audio. The
-    // session is terminated when this call is made and the DidXxxx callbacks
-    // are issued after this call.
+    // session has already been cancelled when this call is made and the DidXxxx
+    // callbacks will not be issued. It is safe to destroy/release the
+    // |SpeechRecognizer| object while processing this call.
     virtual void OnRecognizerError(int caller_id,
                                    SpeechRecognizer::ErrorCode error) = 0;
 
     // At the start of recognition, a short amount of audio is recorded to
     // estimate the environment/background noise and this callback is issued
     // after that is complete. Typically the delegate brings up any speech
     // recognition UI once this callback is received.
     virtual void DidCompleteEnvironmentEstimation(int caller_id) = 0;
 
    protected:
@@ skipping 59 matching lines @@
 
 // This typedef is to workaround the issue with certain versions of
 // Visual Studio where it gets confused between multiple Delegate
 // classes and gives a C2500 error. (I saw this error on the try bots -
 // the workaround was not needed for my machine).
 typedef SpeechRecognizer::Delegate SpeechRecognizerDelegate;
 
 }  // namespace speech_input
 
 #endif  // CHROME_BROWSER_SPEECH_SPEECH_RECOGNIZER_H_