Extend PlatformSpeechSynthesizerMock with an utterance queue.

Source/modules/speech/SpeechGrammarList.cpp

 /*
  * Copyright (C) 2012 Google 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:
  *  * Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  *  * Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 21 matching lines @@
 namespace blink {
 
 SpeechGrammarList* SpeechGrammarList::create()
 {
     return new SpeechGrammarList;
 }
 
 SpeechGrammar* SpeechGrammarList::item(unsigned index) const
 {
     if (index >= m_grammars.size())
-        return 0;
+        return nullptr;
 
-    return m_grammars[index].get();
+    return m_grammars[index];
 }
 
 void SpeechGrammarList::addFromUri(ExecutionContext* executionContext, const String& src, double weight)
 {
     Document* document = toDocument(executionContext);
     m_grammars.append(SpeechGrammar::create(document->completeURL(src), weight));
 }
 
 void SpeechGrammarList::addFromString(const String& string, double weight)
 {
     String urlString = String("data:application/xml,") + encodeWithURLEscapeSequences(string);
     m_grammars.append(SpeechGrammar::create(KURL(KURL(), urlString), weight));
 }
 
 SpeechGrammarList::SpeechGrammarList()
 {
 }
 
 void SpeechGrammarList::trace(Visitor* visitor)
 {
     visitor->trace(m_grammars);
 }
 
 } // namespace blink