Navigator improvements, avoid building invisible routes

R=abarth

Also fixed roll_versions to no longer roll mojo paths
since those are not part of the sky_engine repository.

R=abarth@google.com

The primary goal of this change was to remove EventTarget from the
sky_engine C++ code. Since EventTarget is so core to the entire event
system that sky_engine was based on, this is a rather invasive change.
As such, it had some knock-on effects. I deleted some of the files
that were affected, and cauterised the remainder.

In many cases, a file would depend on another file that it didn't
include directly, but instead included indirectly via another file
that I deleted. When this happened, if the features that this broke
were obsolete, I sometimes just removed the features instead.

Specifically:
- removed EventTarget
- removed EventQueue, since without a target, what's a queue going to
  do?
- same with EventDispatch*
- removed ExecutionContext, since it had an EventQueue and nothing
  else it did was relevant to Sky anymore
- removed ActiveDOMObject, which was all about ExecutionContexts
- removed ContextLifecycleNotifier since it dependend on
  ExecutionContext and ActiveDOMObject
- removed the other Lifecycle classes for consistency, and replaced
  them with four booleans in the Document class
- removed some of the attributes that are no longer relevant from
  IDLExtendedAttributes (ConstructorCallWith and
  CallWith=ExecutionContext)
- removed the Document member on DOMDartState since we never set it to
  anything but null.
- removed BuiltinSky::InstallWindow since it relied on the Document
  member of DOMDartState
- removed EventHandler, EventListener, and mentions of those in
  various binding scripts
- removed NewEventHandler, since we're not using that either
- removed the following interfaces from the Sky Dart API:
  - EventTarget
  - EventListener (since without a target, there's no way to listen)
  - FocusEvent (since it's only member was an EventTarget)
  - HashChangeEvent (mostly by accident, but it's defunct anyway)
  - FontFace (it used ConstructorCallWith=ExecutionContext)
- changed the following interfaces of the Sky DART API:
  - MediaQueryList is no longer an EventTarget
  - Node is no longer an EventTarget
  - Document no longer has defaultView (depended on
    DOMDartState's document)
  - DocumentFragment, Element, Range, and Text no longer have a
    constructor (they all depended on DOMDartState's document, which
    is now gone)
  - Event lost its EventTarget members and path.
  - Window lost its WindowTimers partial interface (it used
    EventTarget and ExecutionContext a lot)
- removed numerous hacks in the bindings around features that are now
  gone, like addEventListener
- removed a bunch of console logging code, since that relied on
  ExecutionContext
- cauterised the wound in FontFace.cpp by removing constructors and
  methods that called now-removed features
- same with MediaQuery and friends
- same with some editor features and focus-related features
- same with Document
- removed DOMTimer classes since they use ExecutionContexts

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1218593002.

Also added a smoke test for examples/widgets/tabs.dart.

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1213873002.

TBR=abarth

Review URL: https://codereview.chromium.org/1208293002.

Let's hide double.INFINITY a bit more, by providing cleaner APIs for the cases where we're currently trying to use it.

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1209233002.

New asserts:
- verify that after layout, the size fits the constraints
- verify that after layout, the size isn't infinite
- verify that you don't set the size in performLayout() if you have
  sizedByParent set
- verify that nobody reads your size during layout except you, or your
  parent if they said parentUsesSize:true

Fixes some bugs found by those asserts:
- RenderBlock, RenderStack, and RenderScaffold were not always setting
  parentUsesSize correctly
- RenderScaffold was setting its slot entries to null rather than
  removing them when the slot went away, which led to null derefs in
  certain circumstances

Also, rename a local variable in RenderStack.performLayout() because
it was shadowing a variable on the object itself, which was really
confusing when I first tried to debug this function...

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1213473003.

There's is no support for animating the selected tab indicator, there isn't a TabNavigator container yet, overflow layout (tabs don't fit) isn't supported yet, etc.

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

Review URL: https://codereview.chromium.org/1205953002.

Adds documentation to Texture and SpriteSheet

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1212073002.

Win was not being detected.

BUG=none
R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1209823002.

This also fixes the C++ side to give the right baseline information.
Previously it was giving the baseline distance for the font, but not
for the actual laid-out text.

I considered also providing a "defaultBaseline" accessor that returns
the distance for the actual dominant baseline, but it turns out right
now we never decide the baseline is ideographic. We always use the
alphabetic baseline. We should probably fix that...

R=eseidel@chromium.org

Review URL: https://codereview.chromium.org/1200233002.

Also, some minor cleanup in TextStyle to make it more readable.

R=eseidel@chromium.org

Review URL: https://codereview.chromium.org/1203253002.

TBR=iansf

Review URL: https://codereview.chromium.org/1201383005.

R=eseidel@chromium.org

Review URL: https://codereview.chromium.org/1208483002.

Decouple Canvas from DisplayList and map Picture and PictureRecorder more directly to their Skia counterparts.

Also changes the framework dart code to use the
refactored APIs and fixes the various examples and
tests.

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

Review URL: https://codereview.chromium.org/1190123003.

Adds drawImageRect to Canvas bindings

R=eseidel@chromium.org

Review URL: https://codereview.chromium.org/1204783003.

I'm not sure I made it look better.  But it uses Widgets
instead of rolling its own Flex, etc.

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

Review URL: https://codereview.chromium.org/1201293003.

R=ianh@google.com, abarth, hixie

Review URL: https://codereview.chromium.org/1201273002.

A very basic minesweeper clone. Currently only tested in linux.

BUG=none
R=abarth@chromium.org, eseidel@chromium.org

Review URL: https://codereview.chromium.org/1196213012.

Also updated the version range on stocks2.

https://github.com/domokit/mojo/issues/262

R=ianh@google.com

Review URL: https://codereview.chromium.org/1195933004.

Make the checkbox in settings control the radio buttons in the drawer, to demonstrate how to link state in different places in an app.

R=jackson@google.com

Review URL: https://codereview.chromium.org/1197333002.

This returns us to a more stocks1-like arrow style.
Also it uses math rather than transforms to rotate the arrow, since transforms are expensive.
It also removes the save/restore calls, which are _really_ expensive.

Also some minor style fixes.

R=eseidel@chromium.org

Review URL: https://codereview.chromium.org/1203443007.

R=ianh@google.com, hixie

Review URL: https://codereview.chromium.org/1204523002.

Short-circuit the relayoutSubtreeRoot when the child couldn't change dimensions anyway because the parent constrained it.

The relayout subtree root concept is intended to handle the case where
a node, when it lays itself out for a second time, changes its opinion
about what dimensions it should be. In such a situation, the parent,
if it based its own opinion about what size _it_ should be on the
child's dimensions, would also need to lay itself out again. Thus,
when this scenario is possible, the child remembers the parent, and
when it would be told to relayout, we actually start the layout with
the parent.

In practice, this chains, and we end up with nodes that point to
ancestors ten or more steps up the tree such that when the inner most
child re-lays-out, the whole app ends up relaying out.

This patch tries to short-circuit this for the case where the
constraints being applied to the child are such that actually, the
child has no choice about its dimensions. In that case, the parent
can't change dimensions when the child re-lays-out.

This makes a huge difference on the stocks demo app. Without this, on
the third rendered frame, there are 72 relayoutSubtreeRoot links, the
deepest chain is 8 deep, and 9 of the chains are only 1 level deep.
With it, there are 63 relayoutSubtreeRoot links, the deepest chain is
only 4 deep, and 38 of the chains are only 1 level deep.

R=eseidel@chromium.org

Review URL: https://codereview.chromium.org/1196553004.

TBR=ianh@google.com

Review URL: https://codereview.chromium.org/1204483002.