chrome/android/java/res/layout/bottom_toolbar_phone.xml

<?xml version="1.0" encoding="utf-8"?>
<!-- Copyright 2016 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. -->

<!-- The toolbar containing the URL bar, back button, and NTP button.
-->

<org.chromium.chrome.browser.toolbar.BottomToolbarPhone
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/toolbar"
    android:layout_width="match_parent"
    android:layout_height="@dimen/toolbar_height_no_shadow" >

    <include layout="@layout/toolbar_phone_common"/>

</org.chromium.chrome.browser.toolbar.BottomToolbarPhone>