[Media Galleries] Lazily initialize the storage monitor.

chrome/browser/extensions/api/media_galleries_private/gallery_watch_state_tracker.h

Index: chrome/browser/extensions/api/media_galleries_private/gallery_watch_state_tracker.h
diff --git a/chrome/browser/extensions/api/media_galleries_private/gallery_watch_state_tracker.h b/chrome/browser/extensions/api/media_galleries_private/gallery_watch_state_tracker.h
index 559497abfb7a2ff409dd2aee3dcb8061b3b8872e..edd7afb4df4fffe678e615e0dea9d61d7721ef4a 100644
--- a/chrome/browser/extensions/api/media_galleries_private/gallery_watch_state_tracker.h
+++ b/chrome/browser/extensions/api/media_galleries_private/gallery_watch_state_tracker.h
@@ -25,6 +25,10 @@ namespace base {
 class Value;
 }
 
+namespace chrome {
+class MediaGalleriesPreferences;
+}
+
 namespace extensions {
 
 class GalleryWatchStateTracker
@@ -66,6 +70,9 @@ class GalleryWatchStateTracker
   // by the |extension_id|.
   void RemoveAllGalleryWatchersForExtension(const std::string& extension_id);
 
+  // Once we learn the preferences, set them in the tracker.
+  void SetPreferences(chrome::MediaGalleriesPreferences* preferences);
+
  private:
   // Key: Gallery identifier.
   // Value: True if the watcher is active. Watcher will be active only if
@@ -87,6 +94,10 @@ class GalleryWatchStateTracker
   void WriteToStorage(const std::string& extension_id);
   void ReadFromStorage(const std::string& extension_id,
                        scoped_ptr<base::Value> value);
+  void ReadFromStorageWithPreferences(
+      const std::string& extension_id,
+      chrome::MediaGalleryPrefIdSet gallery_ids,
+      chrome::MediaGalleriesPreferences* preferences);
 
   // Sets up the gallery watcher on the receipt of granted gallery permission
   // event.
@@ -122,6 +133,9 @@ class GalleryWatchStateTracker
   // Current profile.
   Profile* profile_;
 
+  // The preferences object from which we get gallery information.
+  chrome::MediaGalleriesPreferences* preferences_;
+
   // Used to listen for NOTIFICATION_EXTENSION_LOADED and
   // NOTIFICATION_EXTENSION_UNLOADED events.
   content::NotificationRegistrar registrar_;