Unit test changes:

- add back KevMoo's assertions now that the bugs they exposed ar efixed
- remove onTestResult methods from a couple of configs; these did nothing other
  than prevent the base class implementation from being called which is wrong.
- fix the TestFunction signature
- change from ExpectException, which is deprecated, to TestFailure.
Review URL: https://codereview.chromium.org//12335113

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@19166 260f80e4-7a28-3924-810f-c04153c831b5