- makes the event logic not involve a boolean return value (since we ignored it anyway)
- splits the event handling logic into two steps, hit testing and event dispatch
- introduces an App class on the Dart side to factor out the interaction with the C++ side
- ports sector-layout and simple_render_tree to the new App infrastructure
- port simple_render_tree to the new event handling logic
- implement hit testing for the sector-layout demo
R=eseidel@chromium.org
Review URL: https://codereview.chromium.org/1143343004
- the circle now fills the screen
- you can set dimensions on the solid color node
- debugging printfs and rects are gone
- the protocol is changed so that for sectors, you position before you size (since your size and your childrens' positions all depend on your own position)
TBR=abarth
Review URL: https://codereview.chromium.org/1154213003