Bug 1029031 - Rewrite test to use tasks; r=MattN

An upcoming patch will add more code to
browser_urlbar_search_healthreport.js. We now have support for running
tasks in bc tests, so let's use it to make my life easier.

--HG--
extra : rebase_source : 2fbec7c264f7ebaa8b9abd49694ae56c4d74b7c7
extra : amend_source : 551ee4c0e87f42cd44c9b5395278b56dfbc89b90
Bug 1029031 - Record default search provider in FHR; r=bsmedberg, MattN

--HG--
extra : rebase_source : 7e3c2688db567bac8760c405d9e9d7d41e8564d9
extra : amend_source : a5f4264ec947ae27e3036018034e0b17bf1e8590