GitLab

Follow-up to https://codereview.chromium.org/370813003/ as per request.

BUG=391338
TEST=kInstallDate is still set on startup when it wasn't previously set (and no backup is present in registry)

Review URL: https://codereview.chromium.org/396753005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@283467 0039d316-1c4b-4281-b951-d872f2087c98