webrtc/examples/androidapp/res/layout/activity_call.xml

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

    <android.opengl.GLSurfaceView
        android:id="@+id/glview_call"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <FrameLayout
        android:id="@+id/call_fragment_container"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
    <FrameLayout
        android:id="@+id/hud_fragment_container"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</RelativeLayout>