It has performance implications in release mode.

We'll enable the lint once https://github.com/dart-lang/linter/issues/195 is fixed.

Improve InputValue#toString

Test harness should check for running Timers and AnimationControllers

After running a widget test, we now clear out the widget tree and check that we
didn't leak any timers or animations.

Also, fix several bugs that this addtional check revealed.

Fixes #2481

Adds initial version of Markdown renderer

Add `flutter_tools build` hooks to also generate depfile.

fix a regression in flutter logs

Fixes #1942.

Use lowerBound() from package:collection/collection.dart

Added SizeTransition

fix a npe in lastLogcatTimestamp

Remove //examples/widgets

Most of the remaining widget examples are actually manual tests. This patch
moves them into //dev/manual_tests. A couple are examples of using services,
which I've moved to //examples/layers/services. The remainder are out-dated and
are removed by this patch.

Support undo in the leave-behind demo

Support reparenting state from MultiChildRenderObjectElement

Add ServiceProtocolDiscovery with tests

Fixes #2085

Drop the argument to SceneBuilder's constructor

CheckedPopupMenuItem now fades its icon when changed.

BUG=https://github.com/flutter/flutter/issues/2274

Update engine.version

RenderCustomMultiChildLayoutBox shouldn't be sizedByParent

ImageFit.cover doesn't respect alignment

We need to apply the alignment to the source rect because the ouput rect fills
the destination rect.

Fixes #1514

Be more verbose when downloading artifacts

The getSize function from MultiChildLayoutDelegate might depend on information
other than the incomming constraints.

Fixes #2077

Remove bogus intrinsic size assert

This patch tweaks the definition of max intrinsic size to give implementations
more wiggle room to compute there intrinsic sizes more efficiently.
Specifically, implementations can now ignore the incomming constraint in the
cross axis if they prefer.

This patch removes an assert that is no longer valid w.r.t. the new definition
of intrinsic sizing.

Fixes #2099

Refactor DeviceLogReader