[REG 5.12->5.13]: When causing an update 200ms apart it seems that they end up being combined so there is no visible difference from the first to the second

When causing an update 200ms apart it seems that they end up being combined so there is no visible difference from the first to the second.

In the example attached, clicking the button will trigger an update that causes the inner rectangle not to be drawn, 200ms later it will trigger another update that causes it to be drawn. On all platforms tested, with the exception of macOS 10.12, it will show a flash, indicating that it was not drawn and then drawn again. With macOS 10.12 it will not flash at all, and act as if it was never not drawn.