This moves input.dart to editing2/, since that way we can define the layering as strictly unidirectional.
It also reorders a bunch of imports to fit the style guide.
I removed the old remnants of the widgets example, and put the fn2 examples into the examples/widgets/ directory, to parallel the framework directory names.

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1177243002.

This lays the groundwork for using fn widgets in static environments.

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1178703002

These are now called Block, Stack, and Flex, respectively. Less verbose.

R=jackson@google.com, ianh@google.com

Review URL: https://codereview.chromium.org/1181533002.

This also removes one bit of magic to make it more obvious what on is
going on during a sync, which should hopefully help.

Components have to decide if they support being stateful or not. If
they do, then they must implement syncFields() and have mutable
fields; if they don't, then they must have final fields. This isn't
particularly enforced, though.

This also renames _willSync() to _retainStatefulNodeIfPossible(), for
clarity, and fixes some minor style issues and one typo that was
breaking the drawer.

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1174023003

This would cause them to forget what the most recent child they'd been given was, with disastrous effects later.

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1173683003

The FlexExpandingChild flex parameter is now a keyword as
well, which adds a small readability benefit.

R=ianh@google.com

Review URL: https://codereview.chromium.org/1172503004.

The popup menu is displayed in the wrong location with the wrong width, but it
does draw. I've also removed the checkbox because the flex container was
causing me trouble.  I'll add it back in a later CL.

R=ianh@google.com

Review URL: https://codereview.chromium.org/1166153002

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

The + isn't quite centered properly, but the button is a circle in the right
place.

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

Review URL: https://codereview.chromium.org/1156383004

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

Review URL: https://codereview.chromium.org/1157573012

RenderScaffold needs to attach and detach its children when asked.

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

Review URL: https://codereview.chromium.org/1149893025

Improve the RenderObject.toString() logic so that there's not blank lines everywhere and to generally be better.
Adds sizes, positions, transforms, improves RenderParagraph's output.

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1160233004

Does not work yet.

R=ianh@google.com

Review URL: https://codereview.chromium.org/1163973005

This CL does a bunch of ground work for getting StockList ready for use in
stocks2. It's still not quite working because of an interaction with Scaffold
that we don't fully understand.

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

Review URL: https://codereview.chromium.org/1148793005

R=abarth@chromium.org, abarth

Review URL: https://codereview.chromium.org/1163913004

https://www.dartlang.org/articles/style-guide/#names

R=jackson@google.com

Review URL: https://codereview.chromium.org/1158813004

R=abarth@chromium.org, ianh@google.com, abarth, hixie

Review URL: https://codereview.chromium.org/1165983002

This CL makes gesture events work again in fn2.

R=ianh@google.com

Review URL: https://codereview.chromium.org/1146923005

Not tested on device.

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1160523005

This also works around an Android-only crasher for the Dart VM:
https://github.com/domokit/mojo/issues/192

R=ianh@google.com

Review URL: https://codereview.chromium.org/1157243012

Except that nothing actually uses these now so it's a no-op really.

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1157243011

Also, make the scaffold code more generic (with slots in a map,
instead of dedicated members for each slot).

This may eventually benefit from being split into a general
"multislot" superclass and a scaffold-specific subclass, but for now
it'll do.

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1152163007

Also add operator==, hashCode, toString, and some basic Color constants to
Color.

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

Review URL: https://codereview.chromium.org/1162023004

Looks horrible.  But it's a start.

R=abarth@chromium.org, ianh@google.com
BUG=

Review URL: https://codereview.chromium.org/1146913005

Previously layout2.dart was a thousand lines long.

R=ianh@google.com

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

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/1153223003

R=eseidel@chromium.org

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