Move Extension into extensions namespace

chrome/browser/speech/extension_api/tts_engine_extension_api.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_EXTENSION_API_TTS_ENGINE_EXTENSION_API_H_
 #define CHROME_BROWSER_SPEECH_EXTENSION_API_TTS_ENGINE_EXTENSION_API_H_
 #pragma once
 
 #include "base/memory/singleton.h"
 #include "chrome/browser/extensions/extension_function.h"
 
-class Extension;
 class Utterance;
 
 namespace base {
 class ListValue;
 }
 
+namespace extensions {
+class Extension;
+}
+
 // Return a list of all available voices registered by extensions.
 void GetExtensionVoices(Profile* profile, base::ListValue* result_voices);
 
 // Find the first extension with a tts_voices in its
 // manifest that matches the speech parameters of this utterance.
 // If found, store a pointer to the extension in |matching_extension| and
 // the index of the voice within the extension in |voice_index| and
 // return true.
 bool GetMatchingExtensionVoice(Utterance* utterance,
-                               const Extension** matching_extension,
+                               const extensions::Extension** matching_extension,
                                size_t* voice_index);
 
 // Speak the given utterance by sending an event to the given TTS engine
 // extension voice.
 void ExtensionTtsEngineSpeak(Utterance* utterance,
-                             const Extension* extension,
+                             const extensions::Extension* extension,
                              size_t voice_index);
 
 // Stop speaking the given utterance by sending an event to the extension
 // associated with this utterance.
 void ExtensionTtsEngineStop(Utterance* utterance);
 
 // Hidden/internal extension function used to allow TTS engine extensions
 // to send events back to the client that's calling tts.speak().
 class ExtensionTtsEngineSendTtsEventFunction : public SyncExtensionFunction {
  private:
   virtual ~ExtensionTtsEngineSendTtsEventFunction() {}
   virtual bool RunImpl() OVERRIDE;
   DECLARE_EXTENSION_FUNCTION_NAME("ttsEngine.sendTtsEvent")
 };
 
 #endif  // CHROME_BROWSER_SPEECH_EXTENSION_API_TTS_ENGINE_EXTENSION_API_H_