As in Comment 12 , Black/White area could be related to DXGI_SWAP_EFFECT_FLIP_SEQUENTIAL SwapChain usage and compositor window usage. It looks similar to Bug 1494522. In this case, the symptom seems to related to cpu power.
Bug 1579732 Comment 15 Edit History
Note: The actual edited comment in the bug view page will always show the original commenter’s name and original timestamp.
As in Comment 12 , Black/White area could be related to DXGI_SWAP_EFFECT_FLIP_SEQUENTIAL SwapChain usage and compositor window usage. It looks similar to Bug 1494522. In this case, the symptom seems to related to cpu power. chrome browser also uses DXGI_SWAP_EFFECT_FLIP_SEQUENTIAL SwapChain and child windows in gpu process if possible. It also has similar Black/White area symptom.