We'll eventually turn this into a full fn2 component, but for now it's just an
example.

To make this work, I created a schedule.dart as a start to implementing
scheduler.md. For now, I've kept the API similar to the web platform so that
the old world can continue use it backed by sky.window.requestAnimationFrame.

R=eseidel@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1145973009

Previously layout2.dart was a thousand lines long.

R=ianh@google.com

Review URL: https://codereview.chromium.org/1161003002

R=abarth@chromium.org, eseidel@chromium.org

Review URL: https://codereview.chromium.org/1165463002

R=ianh@google.com

Review URL: https://codereview.chromium.org/1150253005

R=ianh@google.com

Review URL: https://codereview.chromium.org/1146123003

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1158693005

R=ianh@google.com

Review URL: https://codereview.chromium.org/1160843005

Also makes Point, Size, and Rect immutable.

R=ianh@google.com

Review URL: https://codereview.chromium.org/1162033002

R=ianh@google.com

Review URL: https://codereview.chromium.org/1156303004

TBR=ianh@google.com

Review URL: https://codereview.chromium.org/1155103003

I'm sure we'll want something more sophisticated in the near future.

Next step is to actually animate this updating layout.

R=ianh@google.com

Review URL: https://codereview.chromium.org/1150183005

This dramatically simplifies the layout model.
I haven't gone through and simplified the existing functions, we should probably go through and figure out if they can be cleaned up a bit.

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1161983004

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1143153011

This gets things off the ground barely enough to show some pixels.
These are not pixels that are actually part of the stock app, but
it's a start.

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1157033006

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1144193006

TBR=abarth

Review URL: https://codereview.chromium.org/1153273002

Also, fix the style in Rect.cpp/.h.

R=eseidel@chromium.org

Review URL: https://codereview.chromium.org/1158843002

I had to add back document.createText() since new Text()
does not work in the new world yet.

LayoutRoot is a new Dart-exposed class which holds the Frame and
all associated machinery, sufficient to trigger a restyle
and layout of the subtree.

This is all kinda hacky and I'm sure likely to cause many
crashes if folks call random methods on these disconnected
trees.

But this makes it at least possible to paint text for now
and we can improve this in the coming days.

This really should have Adam's review.  It's hugely hacky
but I'd like to negotiate out with him the timeline on
which we should fix some of these hacks.

R=ianh@google.com
TBR=abarth@chromium.org

Review URL: https://codereview.chromium.org/1148253003

This was supposed to be in https://codereview.chromium.org/1153223003

TBR=abarth

Review URL: https://codereview.chromium.org/1160763003

This was supposed to be in https://codereview.chromium.org/1153893006/

TBR=abarth

Review URL: https://codereview.chromium.org/1151383003

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1153893006

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1153223003

R=eseidel@chromium.org

Review URL: https://codereview.chromium.org/1156543004

- 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

R=sethladd@google.com, sethladd

Review URL: https://codereview.chromium.org/1159763003

- 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

Could be useful for watch faces. :-)
Includes some minor fixes to layout2.dart.
Includes adding a very basic path API.

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1152383002

This only handles really basic cases and doesn't understand
justification, wrapping, and so on. Submitting for code
review so I can get some early feedback before I invest
more time into making it correct.

R=ianh@google.com, abarth

Review URL: https://codereview.chromium.org/1151293002

R=ianh@google.com

Review URL: https://codereview.chromium.org/1152603002

R=eseidel@chromium.org

Review URL: https://codereview.chromium.org/1151613005

This demo shows how to create a spinning square using the lowest-level APIs. We
should probably create more spinning square demos at the other layers of the
system.

R=eseidel@chromium.org

Review URL: https://codereview.chromium.org/1147393002

This CL makes simple_render_tree.dart interactive by making the hit testing
system work. I've also added a mechanism for requesting an animation frame.

R=eseidel@chromium.org, ianh@google.com

Review URL: https://codereview.chromium.org/1153543002

This CL teaches simple_render_tree how to do a block layout using layout2.dart.

R=eseidel@chromium.org, ianh@google.com

Review URL: https://codereview.chromium.org/1144423002

This example shows how to draw a circle using subclasses of RenderNode.

R=ianh@google.com

Review URL: https://codereview.chromium.org/1144193004

Clients can now register a callback that gets called whenever we have an event
for the view. We'll need to update the Event class at some point, but this is a
start.

R=eseidel@chromium.org

Review URL: https://codereview.chromium.org/1129333005

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1133353008

This CL teaches SkyView the width, height, and device pixel ratio of the
display. In the future, we'll want some sort of notification system for when
these values change.

R=eseidel@chromium.org

Review URL: https://codereview.chromium.org/1139823010

This CL adds a global view object that can receive a Picture and be signaled to
draw. When using SkyView, this Picture shows up on screen.

R=eseidel@chromium.org

Review URL: https://codereview.chromium.org/1134913003

R=eseidel@chromium.org

Review URL: https://codereview.chromium.org/1145843002

This CL makes the SkyView codepath smart enough to print "hello, world" to the
console. The code path is off by default but can be enabled by changing one
line of code.

R=eseidel@chromium.org

Review URL: https://codereview.chromium.org/1131673011