chrome/android/java/res/drawable/button_compat_shape.xml

<?xml version="1.0" encoding="utf-8"?>
<!-- Copyright 2015 The Chromium Authors. All rights reserved.
     Use of this source code is governed by a BSD-style license that can be
     found in the LICENSE file. -->

<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <solid android:color="@android:color/white" />
    <corners android:radius="@dimen/button_compat_corner_radius" />
</shape>