Disable breaking tests while I investigate the issue. I don't really want to revert;

I want to understand this as it may indicate some other problem.
Review URL: https://codereview.chromium.org//12387033

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@19271 260f80e4-7a28-3924-810f-c04153c831b5