Merge pull request #21296 from 6a68/bug-1032903-erase-all-storages

Bug 1032903 - Erase internal storage if SDcard is default. r=ggp
Bug 1033531 - [Vertical Homescreen] Apps dont appear in custom smart collections if Smart Collection is entered too quickly
Merge pull request #21444 from alivedise/bugzilla/1027401_v2.1/reset-orientation-on-popupclose

Bug 1027401 - Change child event mechanism, r=etienne
Merge pull request #21294 from dominickuo/bug-1009133

Bug 1009133 - [Music] Add hidden style to the player and done icons, r=jimporter
Conflicts:
	shared/test/integration/travis-manifest.json
Merge pull request #21500 from etiennesegonzac/bug-1027231

Bug 1027231 - Making sure windows' height are integers in device pixels. r=alive