When running Metal editor on OSX, resizing windwos or activating and deactivating the OSX Fullscreen mode can cause windows to be cropped and render regions in red.

Repo steps:
1. Load Unity in OSX
2. Make sure you're using Metal editor
3. Play with going into and exiting OSX Fullscreen mode and resizeing windows

Expected results:Windwos should continue to render correctly
Actual results:Windwos can stop being able to expand and instead fill the extra space with red pixels

Repoed:2018.3.0a5

Note: Not sure when in the 18.3 cycle this became worse, it has popped up before but not as bad as this is right now.
Note: Running on 10.13.4 and with a Radeon R9 M370X.
Note: Also happens when disabling/enabling Metal editor