chromium/chrome/android/java/res/layout/drag_drop_target_view.xml

<?xml version="1.0" encoding="utf-8"?>
<!--
Copyright 2023 The Chromium Authors
Use of this source code is governed by a BSD-style license that can be
found in the LICENSE file.
-->

<!-- Width and height are 0 because things inflated from a ViewStub inherit the ViewStub's
     LayoutParams.  Making these 0 so that it's explicit that setting these does nothing. -->
<FrameLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/toolbar_drag_drop_target_view"
    android:layout_width="0dp"
    android:layout_height="0dp"
    android:textAlignment="center"
    android:background="@drawable/target_view_outline"
    android:visibility="gone"/>