@Override
        public Bundle getActiveNotifications() {
            checkCaller();

            return new ActiveNotificationsArgs(
                    TrustedWebActivityService.this.getActiveNotifications()).toBundle();
        }
Used as a return value of {@link #getSmallIconId} when the icon is not provided.
customtabs/src/android/support/customtabs/trusted/TrustedWebActivityService.java