Fix dangerous use of AutoObjCPtr after ownership identity change Metal new* methods create objects with +1 retain count. AutoObjCPtr is intended to adopt this reference. Otherwise, like before this patch, the AutoObjCPtr holds object with +2 count. Before this patch, some but not all call sites donated the extra retain count to autoreleasepool "out of band", and as such the code did not leak that much. Bug: angleproject:6831 Change-Id: I72bcbc712f2cadbcbc6148c6aedfa7e151314518 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3347641 Reviewed-by: John Cunningham <johncunningham@apple.com> Reviewed-by: Kenneth Russell <kbr@chromium.org> Commit-Queue: Jamie Madill <jmadill@chromium.org>