Use MediaGalleryPreferences directly in GalleryWatchStateTracker interface.

chrome/browser/media_galleries/media_galleries_preferences.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_MEDIA_GALLERIES_MEDIA_GALLERIES_PREFERENCES_H_
 #define CHROME_BROWSER_MEDIA_GALLERIES_MEDIA_GALLERIES_PREFERENCES_H_
 
 #include <map>
 #include <set>
 #include <string>
@@ skipping 97 matching lines @@
 typedef std::map<MediaGalleryPrefId, MediaGalleryPrefInfo>
     MediaGalleriesPrefInfoMap;
 typedef std::set<MediaGalleryPrefId> MediaGalleryPrefIdSet;
 
 // A class to manage the media gallery preferences.  There is one instance per
 // user profile.
 class MediaGalleriesPreferences : public BrowserContextKeyedService,
                                   public RemovableStorageObserver {
  public:
   class GalleryChangeObserver {
-    public:
-     // |extension_id| specifies the extension affected by this change.
-     // It is empty if the gallery change affects all extensions.
-     virtual void OnGalleryChanged(MediaGalleriesPreferences* pref,
-                                   const std::string& extension_id) {}
+   public:
+    // |extension_id| specifies the extension affected by this change.
+    // It is empty if the gallery change affects all extensions.
+    virtual void OnGalleryChanged(MediaGalleriesPreferences* pref,
+                                  const std::string& extension_id) {}
 
-    protected:
-     virtual ~GalleryChangeObserver();
+   protected:
+    virtual ~GalleryChangeObserver();
   };
 
   explicit MediaGalleriesPreferences(Profile* profile);
   virtual ~MediaGalleriesPreferences();
 
   void AddGalleryChangeObserver(GalleryChangeObserver* observer);
   void RemoveGalleryChangeObserver(GalleryChangeObserver* observer);
 
   // RemovableStorageObserver implementation.
   virtual void OnRemovableStorageAttached(const StorageInfo& info) OVERRIDE;
@@ skipping 113 matching lines @@
   DeviceIdPrefIdsMap device_map_;
 
   ObserverList<GalleryChangeObserver> gallery_change_observers_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaGalleriesPreferences);
 };
 
 }  // namespace chrome
 
 #endif  // CHROME_BROWSER_MEDIA_GALLERIES_MEDIA_GALLERIES_PREFERENCES_H_