Make Mac SystemInfo reflect the currently active GPU on dual GPU machines Currently, the GetSystemInfo() function (in gpu_info_util/SystemInfo_mac.mm) on dual GPU Macs always updates the active GPU field of the SystemInfo instance to the first non-Intel GPU it finds. This change overrides the activeGPUIndex field of the SystemInfo instance to reflect the current GPU instead of the non-intel GPU. Bug: 985486, 984780, angleproject:3701 Change-Id: Ia93f38f4a2f7728c05e99c83a940722bd3808766 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1752334 Commit-Queue: Kenneth Russell <kbr@chromium.org> Reviewed-by: Zhenyao Mo <zmo@chromium.org> Reviewed-by: Kenneth Russell <kbr@chromium.org>