[ash] Update applist button status when applist is hiding by outside event of

applist button.

R=harrym@chromium.org
BUG=287593
TEST=Compiles, Visual test

Review URL: https://chromiumcodereview.appspot.com/23526030

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@222215 0039d316-1c4b-4281-b951-d872f2087c98

ash/wm/app_list_controller.cc

@@ -188,6 +188,8 @@ void AppListController::SetVisible(bool visible, aura::Window* window) {
           Launcher::ForWindow(window)->GetDragAndDropHostForAppList());
     }
   }
+  // Update applist button status when app list visibility is changed.
+  Launcher::ForWindow(window)->GetAppListButtonView()->SchedulePaint();
 }
 
 bool AppListController::IsVisible() const {