Only send TTS VoicesChanged callbacks when TTS has been explicitly requested.

chrome/browser/speech/tts_controller_impl.cc

 // Copyright 2014 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_impl.h"
 
 #include <string>
 #include <vector>
 
 #include "base/float_util.h"
@@ skipping 419 matching lines @@
       }
 
       return static_cast<int>(i);
     }
   }
 
   return -1;
 }
 
 void TtsControllerImpl::VoicesChanged() {
+  // Existence of platform tts indicates explicit requests to tts. Since
+  // |VoicesChanged| can occur implicitly, only send if needed.
+  if (!platform_impl_)
+    return;
+
   for (std::set<VoicesChangedDelegate*>::iterator iter =
            voices_changed_delegates_.begin();
        iter != voices_changed_delegates_.end(); ++iter) {
     (*iter)->OnVoicesChanged();
   }
 }
 
 void TtsControllerImpl::AddVoicesChangedDelegate(
     VoicesChangedDelegate* delegate) {
   voices_changed_delegates_.insert(delegate);
 }
 
 void TtsControllerImpl::RemoveVoicesChangedDelegate(
     VoicesChangedDelegate* delegate) {
   voices_changed_delegates_.erase(delegate);
 }
 
 void TtsControllerImpl::SetTtsEngineDelegate(
     TtsEngineDelegate* delegate) {
   tts_engine_delegate_ = delegate;
 }
 
 TtsEngineDelegate* TtsControllerImpl::GetTtsEngineDelegate() {
   return tts_engine_delegate_;
 }