Follow up to https://codereview.chromium.org/185423004/

The unzip is always Pro, and without setting this the data.json will
be getting the Express settings and so gyp will generate the wrong
project.

TBR=iannucci@chromium.org
BUG=323300

Review URL: https://codereview.chromium.org/188673003

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@255378 0039d316-1c4b-4281-b951-d872f2087c98