Add support for onvoiceschanged event.

Source/core/platform/mock/PlatformSpeechSynthesizerMock.cpp

 /*
  * Copyright (C) 2013 Apple Computer, Inc.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 15 matching lines @@
 #include "config.h"
 #include "core/platform/PlatformSpeechSynthesisUtterance.h"
 #include "core/platform/mock/PlatformSpeechSynthesizerMock.h"
 
 namespace WebCore {
 
 PassOwnPtr<PlatformSpeechSynthesizerMock> PlatformSpeechSynthesizerMock::create(PlatformSpeechSynthesizerClient* client)
 {
     OwnPtr<PlatformSpeechSynthesizerMock> synthesizer = adoptPtr(new PlatformSpeechSynthesizerMock(client));
     synthesizer->initializeVoiceList();
+    client->voicesDidChange();
     return synthesizer.release();
 }
 
 PlatformSpeechSynthesizerMock::PlatformSpeechSynthesizerMock(PlatformSpeechSynthesizerClient* client)
     : PlatformSpeechSynthesizer(client)
     , m_speakingFinishedTimer(this, &PlatformSpeechSynthesizerMock::speakingFinished)
 {
 }
 
 PlatformSpeechSynthesizerMock::~PlatformSpeechSynthesizerMock()
@@ skipping 45 matching lines @@
     client()->didPauseSpeaking(m_utterance);
 }
 
 void PlatformSpeechSynthesizerMock::resume()
 {
     client()->didResumeSpeaking(m_utterance);
 }
 
 
 } // namespace WebCore