This version calls into presubmit_support directly to support the OWNERS hooks. We do not need both this patch and http://codereview.chromium.org/6646009/

This patch depends on http://codereview.chromium.org/6665018/ .

Review URL: http://codereview.chromium.org/6674014

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@77898 0039d316-1c4b-4281-b951-d872f2087c98