chromium/chrome/browser/ui/android/quickactionsearchwidget/java/res/drawable/quick_action_search_widget_small_button_background.xml

<?xml version="1.0" encoding="utf-8"?>
<!--
Copyright 2021 The Chromium Authors
Use of this source code is governed by a BSD-style license that can be
found in the LICENSE file.
-->

<ripple xmlns:android="http://schemas.android.com/apk/res/android"
    android:color="?android:attr/colorControlHighlight">
    <item android:id="@android:id/mask">
        <shape android:shape="rectangle">
            <solid android:color="@color/default_chip_ripple_color" />
            <corners android:radius="@dimen/quick_action_search_widget_small_button_radius" />
        </shape>
    </item>
    <item>
        <shape android:shape="rectangle">
            <solid android:color="@color/default_bg_color_secondary" />
            <corners android:radius="@dimen/quick_action_search_widget_small_button_radius" />
        </shape>
    </item>
</ripple>