Ignoring the timezone policy if it is set to an empty string.

BUG=176796
TEST=Change timezone as a user, then set timezone device policy to empty string and ensure that it doesn't affect the current timezone.

Review URL: https://chromiumcodereview.appspot.com/12300016

git-svn-id: http://src.chromium.org/svn/trunk/src/chrome/browser/policy/proto@183206 4ff67af0-8c30-449e-8e8b-ad334ec8d88c
1 file changed