Merge pull request #25095 from millermedeiros/1081050-intermittent-da…

…y-observer-test

Bug 1081050 - Intermittent calendar/test/unit/day_observer_test.js | "after each" hook - TypeError: this.connection is null (app://calendar.gaiamobile.org/js/db.js?time=1412932298308:155) r=gaye

apps/calendar/test/unit/day_observer_test.js

@@ -182,8 +182,11 @@ suite('day_observer', function() {
         startDate: today
       });
 
-      subject.on(today, callback);
+      // it's very important to mock clock BEFORE adding listener!!! otherwise
+      // we might get an intermittent race condition (easier to reproduce on
+      // gaia-try and also when running these tests multiple times in a row)
       clock = sinon.useFakeTimers();
+      subject.on(today, callback);
     });
 
     teardown(function() {