chromium/components/webapps/browser/android/java/res/drawable/rating_bar.xml

<?xml version="1.0" encoding="utf-8"?>
<!--
Copyright 2015 The Chromium Authors
Use of this source code is governed by a BSD-style license that can be
found in the LICENSE file.
-->

<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:id="@android:id/background" android:drawable="@drawable/star_gray" />
    <item android:id="@android:id/secondaryProgress" android:drawable="@drawable/star_gray" />
    <item android:id="@android:id/progress" android:drawable="@drawable/star_green" />
</layer-list>