chrome/android/touchless/java/res/drawable/notouch_tooltip_bg.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">

    <solid
        android:color="@color/notouch_tooltip_background" />

    <corners
        android:bottomLeftRadius="8dp"
        android:bottomRightRadius="8dp"
        android:topLeftRadius="8dp"
        android:topRightRadius="8dp" />
</shape>