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

<?xml version="1.0" encoding="utf-8"?>
<!-- Copyright 2019 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. -->

<org.chromium.chrome.browser.toolbar.bottom.ScrollingBottomViewResourceFrameLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content" >

    <LinearLayout
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:id="@+id/bottom_controls_wrapper"
        android:layout_height="wrap_content" >

        <ImageView
            android:id="@+id/bottom_container_top_shadow"
            android:layout_width="match_parent"
            android:layout_height="@dimen/toolbar_shadow_height"
            android:src="@drawable/modern_toolbar_shadow"
            android:scaleType="fitXY"
            android:scaleY="-1"
            tools:ignore="ContentDescription" />

        <FrameLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:id="@+id/bottom_container_slot" >

            <ViewStub
                android:id="@+id/bottom_toolbar_stub"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_gravity="start|bottom"
                android:inflatedId="@+id/bottom_toolbar"
                android:layout="@layout/bottom_toolbar" />

        </FrameLayout>

    </LinearLayout>

</org.chromium.chrome.browser.toolbar.bottom.ScrollingBottomViewResourceFrameLayout>