Revert r11324: Don't run _PopulateGitConfigFile on Mac 10.6
Revert r11324: Don't run _PopulateGitConfigFile on Mac 10.6

Let's see if the 10.6 bots can sync from the mirror now.

R=rmistry@google.com

Review URL: https://codereview.chromium.org/23560011

git-svn-id: 32fc27f4dcfb6c0385cd9719852b95fe6680452d@11335 2bbb7eff-a529-9590-31e7-b0007b416f81

Tiger66639/skia-buildbot,Tiger66639/skia-buildbot,Tiger66639/skia-buildbot,google/skia-buildbot,google/skia-buildbot,Tiger66639/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,Tiger66639/skia-buildbot,google/skia-buildbot,google/skia-buildbot,Tiger66639/skia-buildbot,Tiger66639/skia-buildbot