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

<?xml version="1.0" encoding="utf-8"?>
<!-- Copyright 2017 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. -->

<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item>
        <shape android:shape="rectangle">
            <solid android:color="@color/modern_toolbar_bg" />
        </shape>
    </item>
    <item
        android:top="@dimen/search_toolbar_modern_bg_top_bottom_inset"
        android:bottom="@dimen/search_toolbar_modern_bg_top_bottom_inset"
        android:left="@dimen/search_toolbar_modern_bg_lateral_inset"
        android:right="@dimen/search_toolbar_modern_bg_lateral_inset"
        android:drawable="@drawable/modern_toolbar_background" />
</layer-list>