Fix flaky AppsSearchResultsControllerTest.UninstallReperformsSearch

Also fix the typo "reDperforms".

Since the asynchronous event that the test was waiting for is a Cocoa
event, the QuitClosure was only flakily ensuring that the event was
before it in the message queue. Using the same queue ensures the
messages are properly ordered.

BUG=308828

Review URL: https://codereview.chromium.org/98323002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@238073 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 238073