Access to WebGL Player Settings?

How can I access information such as WebGL Memory Size in a custom editor window / build script.

EditorGUILayout.LabelField("Memory Limit (MB)", PlayerSettings.GetPropertyInt("WebGL Memory Size", BuildTargetGroup.WebGL).ToString());

There doesn’t seem to exist an entry for PlayerSettings.WebGL (unlike other platforms).

(uint)(PlayerSettings.GetPropertyInt(“memorySize”, (BuildTargetGroup)13) * 1024 * 1024)).ToString());