This would case a failure when:
- a .py file is moved
- *.pyc is in svn:ignore, causing the .pyc to not be deleted.
- the new .py modifies its API.
- another .py imports the old .py and uses the new API.

R=dpranke@chromium.org
BUG=
TEST=

Review URL: http://codereview.chromium.org/6854022

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@81942 0039d316-1c4b-4281-b951-d872f2087c98