Fix python tests after r156332.

Apparently I didn't actually run the python tests as part of landing
that change :(.

TBR=ojan@chromium.org
BUG=

Review URL: https://codereview.chromium.org/22886008

git-svn-id: svn://svn.chromium.org/blink/trunk@156337 bbb929c8-8fbe-4397-9dbb-9b2b20218538