Chrome will know when one of its windows has been occluded by others, and will then suspend painting that window’s pixels in an effort to save CPU cycles and battery resources.
An earlier version of this feature, Google said, “had an incompatibility with some virtualization software,” and so it was reworked. (This had been on Chrome 81’s to-do list at one point, but was punted to Chrome 83 before being delayed yet again.) It’s now to appear in Chrome 85, currently scheduled to release Aug. 25.
Administrators will be able to disable this with the NativeWindowOcclusionEnabled policy.