Doing static analysis on the script greatly easy refactoring since it reduces
the chances of leaving a typo in rarely executed & untested & untested code.

This is in preparation to refactor changelist on-disk format to use json.

TEST=none
BUG=none

Review URL: http://codereview.chromium.org/4184008

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@64427 0039d316-1c4b-4281-b951-d872f2087c98