Context: See https://codereview.chromium.org/1934533002/#msg19 for context.

Allows: https://codereview.chromium.org/1933223002

Next - testing that it works for skia, upgrading old users to new method,
and finally killing old code.

R=machenbach@chromium.org,rmistry@chromium.org
BUG=

Review-Url: https://codereview.chromium.org/1927403003

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@300395 0039d316-1c4b-4281-b951-d872f2087c98