Adam Barth e3d587ea52 Move default back behavior to FlutterWidgetBinding
Previously MaterialApp was responsible for ending the activity when the
back stack was empty. However, this behavior is more general than
material. This patch moves the behavior to FlutterWidgetBinding, which
has a global view of all the binding observers.

Fixes #1086
2016-01-07 09:24:51 -08:00
..
2015-12-11 21:05:26 -08:00