Extend PlatformSpeechSynthesizerMock with an utterance queue.

Source/modules/speech/SpeechSynthesis.cpp

 /*
  * Copyright (C) 2013 Apple 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 54 matching lines @@
 
 const HeapVector<Member<SpeechSynthesisVoice>>& SpeechSynthesis::getVoices()
 {
     if (m_voiceList.size())
         return m_voiceList;
 
     // If the voiceList is empty, that's the cue to get the voices from the platform again.
     const HeapVector<Member<PlatformSpeechSynthesisVoice>>& platformVoices = m_platformSpeechSynthesizer->voiceList();
     size_t voiceCount = platformVoices.size();
     for (size_t k = 0; k < voiceCount; k++)
-        m_voiceList.append(SpeechSynthesisVoice::create(platformVoices[k].get()));
+        m_voiceList.append(SpeechSynthesisVoice::create(platformVoices[k]));
 
     return m_voiceList;
 }
 
 bool SpeechSynthesis::speaking() const
 {
     // If we have a current speech utterance, then that means we're assumed to be in a speaking state.
     // This state is independent of whether the utterance happens to be paused.
     return currentSpeechUtterance();
 }
@@ skipping 129 matching lines @@
 }
 
 void SpeechSynthesis::speakingErrorOccurred(PlatformSpeechSynthesisUtterance* utterance)
 {
     if (utterance->client())
         handleSpeakingCompleted(static_cast<SpeechSynthesisUtterance*>(utterance->client()), true);
 }
 
 SpeechSynthesisUtterance* SpeechSynthesis::currentSpeechUtterance() const
 {
-    if (!m_utteranceQueue.isEmpty())
-        return m_utteranceQueue.first().get();
-    return 0;
+    if (m_utteranceQueue.isEmpty())
+        return nullptr;
+
+    return m_utteranceQueue.first();
 }
 
 const AtomicString& SpeechSynthesis::interfaceName() const
 {
     return EventTargetNames::SpeechSynthesis;
 }
 
 void SpeechSynthesis::trace(Visitor* visitor)
 {
     visitor->trace(m_platformSpeechSynthesizer);
     visitor->trace(m_voiceList);
     visitor->trace(m_utteranceQueue);
     PlatformSpeechSynthesizerClient::trace(visitor);
     RefCountedGarbageCollectedEventTargetWithInlineData<SpeechSynthesis>::trace(visitor);
     ContextLifecycleObserver::trace(visitor);
 }
 
 } // namespace blink