/// <summary> /// Compare the two canvases, returning the number of differing pixels and /// the maximum difference in a channel. This will throw an error if /// the dimensions of the two canvases are different. /// /// This method requires UniversalXPConnect privileges. /// </summary> public uint CompareCanvases(GeckoCanvasElement aCanvas1, GeckoCanvasElement aCanvas2, ref uint aMaxDifference) { throw new NotImplementedException(); }