Bug 1029329 - After downloading an app with a role we consider hidden remove it from the grid
Revert "Bug 1026387 - [Dialer][Call log] 'missed' highlighted when tapping edit and back, then tapping 'all'"

This reverts commit 4fd21dac243e496c2a027cda5a1b9d1e97f41b22.
Merge pull request #20917 from lightsofapollo/bug-1029329

Bug 1029329 - After downloading an app with a role we consider hidden re...
Bug 1023179 - Unload video properly, refactor Tutorial init sequence. r=fcampo

* Fix sporadic unencoding error by unloading video before loading new src.
* Refactor Tutorial init to eliminate race-conditions and better manage mixed sequence of asnyc and sync steps
* Use mock XHR for all tutorial tests
* Catch emptied/abort event when unloading video before assigning new src
* Signal media loaded for video via canplay event