framework/web/User.php
protected function removeIdentityCookie()
    {
        Yii::$app->getResponse()->getCookies()->remove(Yii::createObject(array_merge($this->identityCookie, [
            'class' => 'yii\web\Cookie',
        ])));
    }
protected function removeIdentityCookie()
    {
        Yii::$app->getResponse()->getCookies()->remove(Yii::createObject(array_merge($this->identityCookie, [
            'class' => 'yii\web\Cookie',
        ])));
    }
Removes the identity cookie.
This method is used when [[enableAutoLogin]] is true.
@since 2.0.9