Add test specs for a new experimental MSan tester.

Also, add interactive_ui_unittests to the exising tester.

BUG=178409
R=phajdan.jr@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/312833002

git-svn-id: http://src.chromium.org/chrome/trunk/src/testing@274819 4ff67af0-8c30-449e-8e8b-ad334ec8d88c