macOS Sandbox: Fix timezone information on 10.13.

This fixes the sandbox rules to access timezone information specifically
on 10.13.

Bug: 773532
Change-Id: I32dc858a9607b10aa7db4df464a627d02d89b683
Reviewed-on: https://chromium-review.googlesource.com/722203Reviewed-by: Robert Sesek <rsesek@chromium.org>
Commit-Queue: Greg Kerr <kerrnel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#509436}

services/service_manager/sandbox/mac/renderer.sb

@@ -37,7 +37,8 @@
 
 ; https://crbug.com/754280
 (if (param-true? macos-1013)
-  (allow file-read-data (subpath "/usr/share/zoneinfo.default"))
+  (begin (allow file-read-metadata (path "/private/var/db/timezone/zoneinfo"))
+         (allow file-read-data (subpath "/usr/share/zoneinfo.default")))
   (allow file-read-data (subpath "/usr/share/zoneinfo")))
 
 ; Allow access to the metadata of the /etc symlink.