Automatically trigger installation of high-quality speech synthesis extension.

chrome/browser/speech/tts_platform.h

 // Copyright (c) 2012 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_TTS_PLATFORM_H_
 #define CHROME_BROWSER_SPEECH_TTS_PLATFORM_H_
 
 #include <string>
 
 #include "chrome/browser/speech/tts_controller.h"
 
 // Abstract class that defines the native platform TTS interface,
 // subclassed by specific implementations on Win, Mac, etc.
 class TtsPlatformImpl {
  public:
   static TtsPlatformImpl* GetInstance();
 
   // Returns true if this platform implementation is supported and available.
   virtual bool PlatformImplAvailable() = 0;
 
-  // Some platforms may provide a built-in TTS extension. Returns true
-  // if the extension was not previously loaded and is now loading, and
-  // false if it's already loaded or if there's no extension to load.
-  // Will call TtsController::RetrySpeakingQueuedUtterances when
-  // the extension finishes loading.
-  virtual bool LoadBuiltInTtsExtension(Profile* profile);
-
   // Speak the given utterance with the given parameters if possible,
   // and return true on success. Utterance will always be nonempty.
   // If rate, pitch, or volume are -1.0, they will be ignored.
   //
   // The TtsController will only try to speak one utterance at
   // a time. If it wants to interrupt speech, it will always call Stop
   // before speaking again.
   virtual bool Speak(
       int utterance_id,
       const std::string& utterance,
@@ skipping 11 matching lines @@
   // to |out_voices|.
   virtual void GetVoices(std::vector<VoiceData>* out_voices) = 0;
 
   // Pause the current utterance, if any, until a call to Resume,
   // Speak, or StopSpeaking.
   virtual void Pause() = 0;
 
   // Resume speaking the current utterance, if it was paused.
   virtual void Resume() = 0;
 
+  // Allows the platform to monitor speech commands and the voices used
+  // for each one.
+  virtual void WillSpeakUtteranceWithVoice(const Utterance* utterance,
+                                           const VoiceData& voice_data);
+
   virtual std::string error();
   virtual void clear_error();
   virtual void set_error(const std::string& error);
 
  protected:
   TtsPlatformImpl() {}
 
   // On some platforms this may be a leaky singleton - do not rely on the
   // destructor being called!  http://crbug.com/122026
   virtual ~TtsPlatformImpl() {}
 
   std::string error_;
 
   DISALLOW_COPY_AND_ASSIGN(TtsPlatformImpl);
 };
 
 #endif  // CHROME_BROWSER_SPEECH_TTS_PLATFORM_H_