Automatically trigger installation of high-quality speech synthesis extension.

chrome/browser/speech/tts_controller.cc

 // 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.
 
 #include "chrome/browser/speech/tts_controller.h"
 
 #include <string>
 #include <vector>
 
 #include "base/float_util.h"
@@ skipping 148 matching lines @@
   // Select the matching voice, but if none was found, initialize an
   // empty VoiceData with native = true, which will give the native
   // speech synthesizer a chance to try to synthesize the utterance
   // anyway.
   VoiceData voice;
   if (index >= 0 && index < static_cast<int>(voices.size()))
     voice = voices[index];
   else
     voice.native = true;
 
+  GetPlatformImpl()->WillSpeakUtteranceWithVoice(utterance, voice);
+
   if (!voice.native) {
 #if !defined(OS_ANDROID)
     DCHECK(!voice.extension_id.empty());
     current_utterance_ = utterance;
     utterance->set_extension_id(voice.extension_id);
     ExtensionTtsEngineSpeak(utterance, voice);
     bool sends_end_event =
         voice.events.find(TTS_EVENT_END) != voice.events.end();
     if (!sends_end_event) {
       utterance->Finish();
       delete utterance;
       current_utterance_ = NULL;
       SpeakNextUtterance();
     }
 #endif
   } else {
     // It's possible for certain platforms to send start events immediately
     // during |speak|.
     current_utterance_ = utterance;
     GetPlatformImpl()->clear_error();
     bool success = GetPlatformImpl()->Speak(
         utterance->id(),
         utterance->text(),
         utterance->lang(),
         voice,
         utterance->continuous_parameters());
     if (!success)
       current_utterance_ = NULL;
 
-    // If the native voice wasn't able to process this speech, see if
-    // the browser has built-in TTS that isn't loaded yet.
-    if (!success &&
-        GetPlatformImpl()->LoadBuiltInTtsExtension(utterance->profile())) {
-      utterance_queue_.push(utterance);
-      return;
-    }
-
     if (!success) {
       utterance->OnTtsEvent(TTS_EVENT_ERROR, kInvalidCharIndex,
                             GetPlatformImpl()->error());
       delete utterance;
       return;
     }
   }
 }
 
 void TtsController::Stop() {
@@ skipping 90 matching lines @@
 
   // Start speaking the next utterance in the queue.  Keep trying in case
   // one fails but there are still more in the queue to try.
   while (!utterance_queue_.empty() && !current_utterance_) {
     Utterance* utterance = utterance_queue_.front();
     utterance_queue_.pop();
     SpeakNow(utterance);
   }
 }
 
-void TtsController::RetrySpeakingQueuedUtterances() {
-  if (current_utterance_ == NULL && !utterance_queue_.empty())
-    SpeakNextUtterance();
-}
-
 void TtsController::ClearUtteranceQueue(bool send_events) {
   while (!utterance_queue_.empty()) {
     Utterance* utterance = utterance_queue_.front();
     utterance_queue_.pop();
     if (send_events)
       utterance->OnTtsEvent(TTS_EVENT_CANCELLED, kInvalidCharIndex,
                             std::string());
     else
       utterance->Finish();
     delete utterance;
@@ skipping 82 matching lines @@
 }
 
 void TtsController::AddVoicesChangedDelegate(VoicesChangedDelegate* delegate) {
   voices_changed_delegates_.insert(delegate);
 }
 
 void TtsController::RemoveVoicesChangedDelegate(
     VoicesChangedDelegate* delegate) {
   voices_changed_delegates_.erase(delegate);
 }