chrome/android/java/res/drawable-sw600dp/toolbar_shadow.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. -->

<bitmap xmlns:android="http://schemas.android.com/apk/res/android"
    android:src="@drawable/toolbar_shadow_normal"
    android:gravity="top|fill_horizontal" />