Now we use one velocity tracker per pointer.

Path by Kris Giesing.

Fixes #1704

The NewTextPainter is still disabled by default. A future patch will flip the
flag to enable it.

This patch uses a new approach to writing bindings by encoding data into array
buffers. This approach is more efficient than the existing IDL based approach.
If this works out well, we should convert our other performance-sensitive
interfaces to this approach in future patches.

Now AssetImage will look in the default bundle if you don't supply an explicit
bundle.

Fixes #680

Add .gitignore file to the flx package

Use FractionalOffset alignment value in Stack and IndexedStack

The magic for updating DebugSize's knowledge about whether it was
allowed to be used by the parent or not previously failed to correctly
deal with sizedByParent.

Unmatched heroes don't need to animate

Fix slow sound init in piano sample app

Fixes #1696. Also fixes handles leaking on error.

By default now heroes won't animate if they don't find a matching hero
on the target page. You can make them animate by setting 'alwaysAnimate:
true' on the Hero constructor.

Adds a dropdown menu button as shown in the Material design spec here: https://www.google.com/design/spec/components/buttons.html#buttons-dropdown-buttons. It's the video at the bottom of this section of the Material design spec.

This version of the component doesn't deal with scrollable menus or
constrain the height of the menu.

Now you don't need to pass the navigator around everywhere.

Fix a type mismatch in IconThemeData.operator==

Export gridpaper.dart

Create new 'flx' package. Just a copy for now.

This will be shared by sky/updater and flutter_tools. Currently
bundle.dart and signing.dart are unmodified copies of the files from
updater and flutter_tools, respectively. This is so future changes are
easier to see.

This grid makes it significantly easier to track down errors when you're
looking at coordinates in a render tree dump and want to see if they're
what you expect or if they're wildly away from the right location.

These new PerformanceView classes are transforms over PerformanceViews.
The first is a cheap way to tell code that expects a performance to not
animate after all, and the other is a way to replace a view of a
performance going in one direction with a view of a performance going in
the other direction.

See also https://github.com/flutter/engine/issues/1708

A transition that rotates its contents.

Assert at build time that PageRoute route builders do not return null
widget trees.

Also very minor new code comments and code reorg to help make the heroes
patch easier to review.

(These are changes that are unrelated to Heroes but that were part of
the Heroes patch.)

UniqueKey

Sometimes you need a Key (not a GlobalKey) that is only equal to itself
but can be used multiple times in the tree. Enter UniqueKey!

The 0.2.1 release of the mojo package isn't actually compatible with Flutter
despite claiming to be a minor release. The real fix is to make Flutter
compatible with that release, but there are several yak shaves involved.

First pass on sprite physics node hierarchy integration