chrome/android/java/res/drawable/item_chooser_row_background.xml

<?xml version="1.0" encoding="utf-8"?>
<!-- Copyright 2016 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.
-->
<selector xmlns:android="http://schemas.android.com/apk/res/android">
  <item android:drawable="@color/light_active_color" android:state_activated="true"/>
  <item android:drawable="@android:color/transparent"/>
</selector>