Move Extension into extensions namespace

chrome/browser/speech/extension_api/tts_engine_extension_api.h

Index: chrome/browser/speech/extension_api/tts_engine_extension_api.h
diff --git a/chrome/browser/speech/extension_api/tts_engine_extension_api.h b/chrome/browser/speech/extension_api/tts_engine_extension_api.h
index eea8aa869c6f3b995bfcbe5cb512187bece93147..c8653cb79c0b44dbb81b9b3c1d5f747cecb7ee50 100644
--- a/chrome/browser/speech/extension_api/tts_engine_extension_api.h
+++ b/chrome/browser/speech/extension_api/tts_engine_extension_api.h
@@ -9,13 +9,16 @@
 #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);
 
@@ -25,13 +28,13 @@ void GetExtensionVoices(Profile* profile, base::ListValue* result_voices);
 // 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