Make clear why do we reload collection view when changing group before syncing data.

Author: SergioEstevao

Pod/Classes/WPMediaCollectionViewController.m

@@ -237,6 +237,9 @@ - (void)refreshData
             [self.collectionView setContentOffset:CGPointMake(0, - [[self topLayoutGuide] length] - (self.refreshControl.frame.size.height)) animated:YES];
             [self.refreshControl beginRefreshing];
         }
+        // NOTE: Sergio Estevao (2015-11-19)
+        // Clean all assets and refresh collection view when the group was changed
+        // This avoid to see data from previous group while the new one is loading.
         [self.collectionView reloadData];
     }
     self.collectionView.allowsSelection = NO;