Roll goldctl (mac) from H_4GgcW8C... to oxKWG6EzN...

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/goldctl-mac-chromium-autoroll
Please CC bsheedy@chromium.org on the revert to ensure that a human
is aware of the problem.

To report a problem with the AutoRoller itself, please file a bug:
https://bugs.chromium.org/p/skia/issues/entry?template=Autoroller+Bug

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+doc/master/autoroll/README.md

Bug: None
Tbr: bsheedy@chromium.org
Change-Id: Ic93ba719014ffcd7b3bdcf3c6b7f84fcd71cda57
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2616921Reviewed-by: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Commit-Queue: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#841354}

DEPS

@@ -1576,7 +1576,7 @@ deps = {
       'packages': [
         {
           'package': 'skia/tools/goldctl/mac-amd64',
-          'version': 'H_4GgcW8CtnxDnWd7RX17C39CAYzfHUaFR6drL3wWAcC',
+          'version': 'oxKWG6EzN6FHwQ-4J6gUYMHuNuHyARpVl4EvirOsXSgC',
         },
       ],
       'dep_type': 'cipd',