if (mGoogleApiClient != null && mGoogleApiClient.isConnected()) {
            Auth.GoogleSignInApi.signOut(mGoogleApiClient).setResultCallback(
                    new ResultCallback<Status>() {
                        @Override
                        public void onResult(Status status) {

                        }
                    });
        }

Auth.GoogleSignInApi.signOut(mGoogleApiClient)