Launcher-side changes to support prediction bar.

Change-Id: Ib9974ad8888ad87137c774f9f531fae9d56b899a

src/com/android/launcher3/LauncherExtension.java

@@ -127,6 +127,10 @@ public class LauncherExtension extends Launcher {
         public void onAllAppsShown() {
         }
 
+        @Override
+        public void onAllAppsHidden() {
+        }
+
         @Override
         public void bindAllApplications(ArrayList<AppInfo> apps) {
         }