chromium/components/browser_ui/widget/android/java/res/drawable-v23/app_menu_bg.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.
-->

<layer-list
    xmlns:android="http://schemas.android.com/apk/res/android">
    <item
        android:top="@dimen/app_menu_shadow_length"
        android:left="@dimen/app_menu_shadow_length"
        android:bottom="@dimen/app_menu_shadow_length"
        android:right="@dimen/app_menu_shadow_length">
        <shape
            android:shape="rectangle">
            <corners android:radius="@dimen/app_menu_corner_size" />
            <solid android:color="@color/menu_item_bg_color_baseline" />
            <padding
                android:top="@dimen/app_menu_shadow_length"
                android:left="@dimen/app_menu_shadow_length"
                android:bottom="@dimen/app_menu_shadow_length"
                android:right="@dimen/app_menu_shadow_length" />
        </shape>
    </item>
</layer-list>