PRESUBMIT.py: Run only PRESUBMIT_test.py if PRESUBMIT.py changes.

Previously, we used to run all _test.py files in this directory.

BUG=NONE
NOTRY=true


Review URL: https://chromiumcodereview.appspot.com/12037006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@177927 0039d316-1c4b-4281-b951-d872f2087c98
1 file changed