Added InitTts function to speech synthesis library

chrome/browser/chromeos/cros/speech_synthesis_library.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_CHROMEOS_CROS_SPEECH_SYNTHESIS_LIBRARY_H_
 #define CHROME_BROWSER_CHROMEOS_CROS_SPEECH_SYNTHESIS_LIBRARY_H_
 
 #include "base/singleton.h"
 
 namespace chromeos {
 
 // This interface defines the interaction with the ChromeOS login library APIs.
 class SpeechSynthesisLibrary {
  public:
+  typedef void(*InitStatusCallback)(bool success);
+
   virtual ~SpeechSynthesisLibrary() {}
   // Speaks the specified text.
   virtual bool Speak(const char* text) = 0;
   // Sets options for the subsequent speech synthesis requests.
   virtual bool SetSpeakProperties(const char* props) = 0;
   // Stops speaking the current utterance.
   virtual bool StopSpeaking() = 0;
   // Checks if the engine is currently speaking.
   virtual bool IsSpeaking() = 0;
+  // Starts the speech synthesis service and indicates through a callback if
+  // it started successfully.
+  virtual void InitTts(InitStatusCallback) = 0;
 };
 
 // This class handles the interaction with the ChromeOS login library APIs.
 class SpeechSynthesisLibraryImpl : public SpeechSynthesisLibrary {
  public:
   SpeechSynthesisLibraryImpl() {}
   virtual ~SpeechSynthesisLibraryImpl() {}
 
   // SpeechSynthesisLibrary overrides.
   virtual bool Speak(const char* text);
   virtual bool SetSpeakProperties(const char* props);
   virtual bool StopSpeaking();
   virtual bool IsSpeaking();
+  virtual void InitTts(InitStatusCallback);
 
  private:
   DISALLOW_COPY_AND_ASSIGN(SpeechSynthesisLibraryImpl);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_CROS_SPEECH_SYNTHESIS_LIBRARY_H_