iceraven-browser/app/src/main/res/drawable/media_state_background.xml

<?xml version="1.0" encoding="utf-8"?>
<!-- This Source Code Form is subject to the terms of the Mozilla Public
   - License, v. 2.0. If a copy of the MPL was not distributed with this
   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="oval">
    <size
        android:width="24dp"
        android:height="24dp" />
    <!-- Background color of the circle -->
    <solid android:color="?tabTrayItemMediaBackground" />
    <!-- Outer circle border -->
    <stroke android:color="@color/tab_tray_item_media_stroke"
        android:width="2dp"/>
</shape>