[Media Galleries] Lazily initialize the storage monitor.

chrome/browser/media_galleries/media_galleries_preferences.cc

Index: chrome/browser/media_galleries/media_galleries_preferences.cc
diff --git a/chrome/browser/media_galleries/media_galleries_preferences.cc b/chrome/browser/media_galleries/media_galleries_preferences.cc
index c287739800ef21e2ddbe2f4949e15749b5e531b8..88ed758e162f06db1eab6ffc0455b2dab108d9be 100644
--- a/chrome/browser/media_galleries/media_galleries_preferences.cc
+++ b/chrome/browser/media_galleries/media_galleries_preferences.cc
@@ -639,7 +639,7 @@ void MediaGalleriesPreferences::SetGalleryPermissionForExtension(
 #if defined(ENABLE_EXTENSIONS)
       if (state_tracker) {
         state_tracker->OnGalleryPermissionChanged(extension.id(), pref_id,
-                                                  true);
+                                                  true, this);
       }
 #endif
       return;
@@ -657,7 +657,7 @@ void MediaGalleriesPreferences::SetGalleryPermissionForExtension(
 #if defined(ENABLE_EXTENSIONS)
   if (state_tracker) {
     state_tracker->OnGalleryPermissionChanged(extension.id(), pref_id,
-                                              has_permission);
+                                              has_permission, this);
   }
 #endif
 }