Revert "Merge pull request #10387 from rexboy7/fix-bug840147-bug877903-v1train"

This reverts commit d55d2d2d2317b09cc61404ec6d23c0346e9e006b, reversing
changes made to 9c9f1445afadcfd7078311341d35800f696fc90d.
Bug 881584 - Stop video activity when visibility is changed.
Merge pull request #10684 from alivedise/bugzilla/881584_v1-train_v2

Bug 881584 - Stop video activity when visibility is changed. r=djf, a=leo+
Bug 885584 - [B2G][SMS/MMS] Thumbnails are invisible in the preview attachment with large files - r=julienw

* Sets max thumbnail generation size to 1.5 megs, which should be big enough for any mms image
* Removes a var self = this;
(cherry picked from commit b17b09bf8526be355e2e56a31942c6d9b9d3adab)
Bug 840147 & Bug 877903 : fix orientation problem on open/close app animation.
                          * Open app by real device orientation
                          * Refactor setAppSize and rotateTransition to AppWindow