chromium/components/browser_ui/photo_picker/android/java/res/drawable/video_player_gradient.xml

<?xml version="1.0" encoding="utf-8"?>
<!--
Copyright 2020 The Chromium Authors
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">
    <gradient
        android:type="linear"
        android:angle="90"
        android:startColor="@android:color/black"
        android:centerColor="@color/black_alpha_30"
        android:centerY="0.72"
        android:endColor="@android:color/transparent" />
</shape>