Now that we have all the Dart packages we need in //third_party, we can build
skyx bundles by default.

As part of this change, I've made it possible to build skyx bundles on Linux
and I've made the gn target names of the mojoms in //sky/services consistent
with each other and with //mojo/services/public.

TBR=eseidel@google.com

Review URL: https://codereview.chromium.org/1227973002 .

Some minor cleanup. Also created a small mess to work around
https://github.com/domokit/mojo/issues/312

- Track event.dx sum; don't listen to the card container
- Support dismissing to the left (too)
- Slow the dismiss "fling" animation down a little.

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1231693003 .

```yaml
Missing requirements:
* Older versions of pub don't support ^ version constraints.
  Make sure your SDK constraint excludes those old versions:

  environment:
    sdk: ">=1.8.0 <2.0.0"

  Or use a fully-expanded constraint:

  dependencies:
    cassowary: ">=0.1.6 <0.2.0"
```

Sorry, your package is missing a requirement and can't be published yet.

Review URL: https://codereview.chromium.org/1225303002 .

BUG=

Review URL: https://codereview.chromium.org/1231803003 .

- Pub doesn't publish dot files (who knew?!)
- sky_tool was referencing a variable that doesn't exist

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1223173003 .

We need to test for visual overflow after writing size because we need to use
the up-to-date value of size.

TBR=ianh@google.com

Review URL: https://codereview.chromium.org/1230733002 .

The core parts of RenderBlock will be reused by: https://codereview.chromium.org/1222913013/

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1226103003 .

Provide an API that allows a RenderObject's performLayout() function to call a callback that mutates the render tree during layout.

Also, provide a removeAll() function on ContainerRenderObjectMixin.

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1229793002 .

There are basically three tricks here:
- Making retainStatefulNodeIfPossible non-private, so that
  RenderObjectWrappers in other files can use it.
- RenderObjectWrappers have a utility function that subclasses
  can call (retainStatefulRenderObjectWrapper()) to enable them
  to be retained, when they override retainStatefulNodeIfPossible.
- enterLayoutCallbackBuilder()/exitLayoutCallbackBuilder() API to set
  the right flags so that you can build Widget nodes outside a
  regular build cycle

Also:
- Widget.toStringName(), for debugging when you don't want the whole
  subtree printed.

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1225123005 .

Using mirrors prevents some static analysis tools from working on Sky.

R=ianh@google.com

Review URL: https://codereview.chromium.org/1224133002 .

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1230583003 .

Also, make stocks robust to failing network connections.

TBR=eseidel@google.com

Review URL: https://codereview.chromium.org/1229743002 .

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

Review URL: https://codereview.chromium.org/1227843002 .

WIP -- need to update some tests at the least.

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

Review URL: https://codereview.chromium.org/1216833003 .

BUG=
R=eseidel@chromium.org

Review URL: https://codereview.chromium.org/1231653002 .

Material-style card dismissal. Many things remain to be done:

- Track event.dx sum; don't listen to the card container
- Make this a feature of Card
- Support dismissing to the left (too)
- Animate the layout change caused by dismissing the card
- Deal with many cards animating away at the same time
- Integrate with TBD VariableHeightScrollable

This version just exists to collect a little feedback,
including about the use of AnimationPerformance

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1231603003 .

I added a clip in RenderBlock to make the painted pixels
match the hittesting logic.  This at least makes obvious
all the numerous hittesting bugs in our system. :)

I also moved demo_launcher to ScrollableList awesomeness.

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

Review URL: https://codereview.chromium.org/1223083002 .

This interface is growing to expose many activity-related functions, more than
just intents.

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

Review URL: https://codereview.chromium.org/1223053002 .

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

Review URL: https://codereview.chromium.org/1208993020 .

BUG=
R=eseidel@chromium.org

Review URL: https://codereview.chromium.org/1225923009 .

TBR=abarth@google.com

Review URL: https://codereview.chromium.org/1222193008 .

TBR=abarth@chromium.org

Review URL: https://codereview.chromium.org/1223003002 .

This patch makes the call to rmtree that wipes the already downloaded
icons pass if the directory is not present yet.

R=qsr@chromium.org

Review URL: https://codereview.chromium.org/1226833009 .

This CL is an experiment in adding some dartdoc comments in a few places. It's
unclear how extensively we'll use dartdoc.

TBR=ianh@google.com

Review URL: https://codereview.chromium.org/1207373005 .

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1213603006 .

R=ianh@google.com

Review URL: https://codereview.chromium.org/1226583005 .

R=abarth@chromium.org, abarth

Review URL: https://codereview.chromium.org/1223843014 .

TBR=abarth@google.com

Review URL: https://codereview.chromium.org/1216053015 .

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

Review URL: https://codereview.chromium.org/1227663003 .

R=eseidel@chromium.org

Review URL: https://codereview.chromium.org/1215313004 .

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

Review URL: https://codereview.chromium.org/1218293017 .

When run with a root bundle, the Stocks app now fetches its data from the
Internet.

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

Review URL: https://codereview.chromium.org/1208053008 .

This isn't quite perfect since we seem to do a second layout as the
activity switcher is brought up which is shifting down our
toolbar and making it bleed slightly below the Activity Switcher's
Task description bar.  But at least we're the right color now.

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

Review URL: https://codereview.chromium.org/1209423008 .

This file will be used by a future version of the Dart analyzer to understand
Dart code that uses the dart:sky package.

R=johnmccutchan@google.com

Review URL: https://codereview.chromium.org/1214433006 .

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

Review URL: https://codereview.chromium.org/1214633008 .

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

Review URL: https://codereview.chromium.org/1214073014.

R=abarth@chromium.org, hixie

Review URL: https://codereview.chromium.org/1209423006.

From SkyDemo.apk.

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

Review URL: https://codereview.chromium.org/1221143003 .

A ScrollableList seems like a generically useful widget.

R=ianh@google.com

Review URL: https://codereview.chromium.org/1223863003 .

Previously, if a subclass of FixedHeightScrollable didn't set itemCount,
everything would silently work except that you wouldn't actully be able to
scroll. This CL makes it harder to forget to provide the itemCount by making it
an abstract getter. Now the analyzer will flag it as missing in subclasses and
we'll throw an exception at runtime if you forget it.

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

Review URL: https://codereview.chromium.org/1219933004 .