Fixed JetPlayer initialization code and pause when the app loses focus.
Removed mute mask hack.
Cleaned up event ID declaration and check (event value is a byte, not a String).
Add extensive comments for the JetPlayer code.
BUG=1596727
Automated import of CL 146643
- use theme instead of window feature to remove titlebar
- remove useless Layouts
- Make custom view works in layout editor.
- remove some warnings
BUG=1596727
Automated import of CL 144565
