mac: Permit Mach lookup of com.apple.system.opendirectoryd.membership in gpu_v2

This is needed to look up the Metal cache directory, which is used for
graphics acceleration by various system frameworks.

Bug: 1126350
Change-Id: I79e05c603859aa49082fbbbc09c1da9b4ae3a990
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2411151
Auto-Submit: Robert Sesek <rsesek@chromium.org>
Commit-Queue: Greg Kerr <kerrnel@chromium.org>
Reviewed-by: Greg Kerr <kerrnel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#806776}

sandbox/policy/mac/gpu_v2.sb

@@ -27,6 +27,7 @@
   (global-name "com.apple.PowerManagement.control")
   (global-name "com.apple.SecurityServer")
   (global-name "com.apple.system.notification_center")
+  (global-name "com.apple.system.opendirectoryd.membership") ; https://crbug.com/1126350#c5
   (global-name "com.apple.tsm.uiserver")
   (global-name "com.apple.windowserver.active")
 )