Tweaked the layout in Scaffold a little: the Scaffold
accounts for the (Android) notification bar's height,
instead of the ToolBar. I think it would be best if
moving the app below the notification area were handled
at a lower level. Doing it in Scaffold seemed OK for the
moment, since one could put a ToolBar component anywhere
in an app.
Closes#208R=ianh@google.com
Review URL: https://codereview.chromium.org/1171173003.
This includes making SizedBox default to infinite size, and making
Container default to containing one infinite-sized SizedBox. That way,
you can use an empty Container as a spacer in a flex box.
The rendering doesn't quite work, because of a bug in flex whereby it
doesn't shrink-wrap its contents in the cross-direction, it fills the
parent. Collin is on that.
R=jackson@google.com
Review URL: https://codereview.chromium.org/1163633003
