gclient sync, revert and status are tested.

GClientSmokeGIT.testRevertAndStatus is known to fail since git-backed revert doesn't work.

Review URL: http://codereview.chromium.org/2189001

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@48239 0039d316-1c4b-4281-b951-d872f2087c98