We currently assume that the first renderer returned by CGLQueryRendererInfo is the current GPU. I believe this is a correct assumption, but it would be safer to use the Metal function CGDirectDisplayCopyCurrentMetalDevice.
Created attachment 350236 [details] Patch
Attachment 350236 [details] did not pass style-queue: ERROR: Source/WebCore/ChangeLog:12: You should remove the 'No new tests' and either add and list tests, or explain why no new tests were possible. [changelog/nonewtests] [5] Total errors found: 1 in 3 files If any of these errors are false positives, please file a bug against check-webkit-style.