chrome/android/java/res/drawable/drag_handlebar.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. -->

<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
    <size android:height="4dp"
        android:width="40dp"/>
    <corners
        android:radius="2dp" />
    <solid android:color="@color/drag_handlebar_color" />
</shape>