Uses a system-wide notion of isSpeaking in the Mac extension TTS api.

chrome/browser/speech/extension_api/tts_extension_api_controller_unittest.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.
 
 // Unit tests for the TTS API Controller.
 
 #include "testing/gtest/include/gtest/gtest.h"
 
 #include "base/values.h"
 #include "chrome/browser/speech/extension_api/tts_extension_api_controller.h"
 #include "chrome/browser/speech/extension_api/tts_extension_api_platform.h"
 
 class ExtensionTtsApiControllerTest : public testing::Test {
 };
 
 // Platform Tts implementation that does nothing.
 class DummyExtensionTtsPlatformImpl : public ExtensionTtsPlatformImpl {
  public:
   DummyExtensionTtsPlatformImpl() {}
   virtual ~DummyExtensionTtsPlatformImpl() {}
   virtual bool PlatformImplAvailable() { return true; }
   virtual bool Speak(
       int utterance_id,
       const std::string& utterance,
       const std::string& lang,
       const UtteranceContinuousParameters& params) {
     return true;
   }
+  virtual bool IsSpeaking() { return false; }
   virtual bool StopSpeaking() { return true; }
   virtual bool SendsEvent(TtsEventType event_type) { return false; }
   virtual std::string gender() { return std::string(); }
   virtual std::string error() { return std::string(); }
   virtual void clear_error() {}
   virtual void set_error(const std::string& error) {}
 };
 
 // Subclass of ExtensionTtsController with a public ctor and dtor.
 class TestableExtensionTtsController : public ExtensionTtsController {
@@ skipping 15 matching lines @@
 
   Utterance* utterance2 = new Utterance(NULL);
   utterance2->set_can_enqueue(true);
   utterance2->set_src_id(2);
   controller->SpeakOrEnqueue(utterance2);
 
   // Make sure that deleting the controller when there are pending
   // utterances doesn't cause a crash.
   delete controller;
 }