Reinstall the hotword shared module on a lanuage change.

chrome/browser/search/hotword_service.h

 // Copyright 2013 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_SEARCH_HOTWORD_SERVICE_H_
 #define CHROME_BROWSER_SEARCH_HOTWORD_SERVICE_H_
 
 #include "base/basictypes.h"
 #include "base/memory/weak_ptr.h"
 #include "base/prefs/pref_change_registrar.h"
@@ skipping 108 matching lines @@
   enum LaunchMode {
     AUDIO_HISTORY_ONLY,
     HOTWORD_ONLY,
     HOTWORD_AND_AUDIO_HISTORY,
     SPEECH_TRAINING
   };
   void LaunchHotwordAudioVerificationApp(const LaunchMode& launch_mode);
   virtual LaunchMode GetHotwordAudioVerificationLaunchMode();
 
  private:
+  // Returns the ID of the extension that may need to be reinstalled.
+  std::string ReinstalledExtensionId();
+
   Profile* profile_;
 
   PrefChangeRegistrar pref_registrar_;
 
   content::NotificationRegistrar registrar_;
 
   // For observing the ExtensionRegistry.
   ScopedObserver<extensions::ExtensionRegistry,
                  extensions::ExtensionRegistryObserver>
       extension_registry_observer_;
 
   scoped_refptr<extensions::WebstoreStandaloneInstaller> installer_;
 
   HotwordClient* client_;
   int error_message_;
   bool reinstall_pending_;
 
   base::WeakPtrFactory<HotwordService> weak_factory_;
 
   // Stores the launch mode for the Hotword Audio Verification App.
   LaunchMode hotword_audio_verification_launch_mode_;
 
   DISALLOW_COPY_AND_ASSIGN(HotwordService);
 };
 
 #endif  // CHROME_BROWSER_SEARCH_HOTWORD_SERVICE_H_