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

<?xml version="1.0" encoding="utf-8"?>
<!-- Copyright 2020 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. -->

<FrameLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/context_menu_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@android:color/transparent">

    <ViewStub
        android:id="@+id/context_menu_stub"
        android:layout="@layout/context_menu"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginHorizontal="@dimen/context_menu_lateral_margin"
        android:layout_marginVertical="@dimen/context_menu_vertical_margin"
        android:layout_gravity="center"/>

    <!-- Anchor point for AnchoredPopupWindow displaying optional chip. -->
    <View
        android:id="@+id/context_menu_chip_anchor_point"
        android:layout_width="0px"
        android:layout_height="0px"
        android:layout_marginTop="@dimen/context_menu_chip_vertical_margin"
        android:layout_marginBottom="@dimen/context_menu_chip_vertical_margin"
        android:layout_gravity="bottom|center_horizontal"/>
</FrameLayout>