shell handle.

R=@abarth,@tonygentilcore

Add a persistent bottom sheet to the stocks demo

Move data out of Github and into Firebase

@abarth @collinjackson

Fix adb parse

Update to match Hixie's changed bash script

Adding windows batch file to complement the bash script.

Raw keyboard example

Update the raw examples to handle PointerPacket events

Give loose contraints to text inside input widget

Named parameters for the mock_events.dart TestPointer class

The input widget scrolls, so it should give its text loose constraints.  That
way the text ends up being its intrinsic size even if put in a context with
tight constraints.

Fixes #298

Add a unit test for persistent bottom sheets

ShowBottomSheet now clears its placeholder after the bottom sheet has been dismissed.

Added support for generating fling gestures to WidgetTester.

Receive pointer events through PointerPackets

Fix remaining analyzer warnings

Constructor tear-offs aren't supported by the analyzer yet.

Fix analyzer warnings in mojo_client.dart

Rename sky_tools to flutter_tools

Don't run these benchmarks forever by default

Running forever is useful for profiling but makes these scripts less useful for
measurement.  :)

Move Python script over to Dart.

Run 'pub get' the first time the tests are run

Make layout_bench.dart 19% faster

Previously we would walk from every node in layout to the root to mark the root
as needing paint. Now we leave dirty bits throughout the tree so that we can
cut off the walk as soon as we find a dirty node.

Refactor bottom sheet support, add one to the stocks demo

Factored OverlayRoute out of the modal and persistent bottom sheet classes, since the bottom sheet classes need to drive the performance.

Added a bottom sheet to the stocks demo: long-press on a stock shows a modal bottom sheet.

Made AnimatedModalBarrier public.

Factored OverlayRoute out of the modal and persistent bottom sheet clases, since the bottom sheet classes need to drive the performance.

Added a bottom sheet to the stocks demo: long-press on a stock shows a modal bottom sheet.

Made AnimatedModalBarrier public.