This is just making the same change to the copy of upload.py that is in depot_tools.

BUG=419156
R=iannucci@chromium.org

Original Review URL: https://codereview.chromium.org/624513002

Review URL: https://codereview.chromium.org/639503002

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@292432 0039d316-1c4b-4281-b951-d872f2087c98