* Let lists automatically add sliver padding from media query. Translucent nav and tab bars leave behind media query paddings in scaffolds.

* tests

* const lint

* Rename base abstract class to generalized ObstructingPreferredSizeWidget

* Add MediaQuery support for view insets

Also updates EdgeInsets documentation to reflect WindowPadding's use for
both padding and view insets.

See engine commits:
  flutter/engine#4403
  flutter/engine#4406

Fixes the remaining known issues with widgets supporting RTL.

* ensures that only semantics boundaries will be added to owner._nodesNeedingSemantics as expected by compiler.
* no longer throws assert if markNeedsSemanticsUpdate is called on non-semantic-boundary render object with a non-semantic-boundary parent.
* Fixes #13109.
* removes onlyLocalUpdates from markNeedsSemanticsUpdate as its no longer needed.

* Change some of the dev/devicelab tests to support testing against local engine.

We can already configure flutter tools to use local engine by setting
FLUTTER_ENGINE environment variable. However when this variable is set
this also requires setting --local-engine to specify which flavor of
engine to use.

This change changes tests in dev/devicelab to pass a sensible default for
--local-engine, e.g. when testing hot reload on Android we pass android_debug
and when testing release AOT build for IOS we pass ios_release.

* Fix analysis issues

* Update utils.dart

Roll engine to 77b2d1d95a9438ff996d24ef3e0b3ec81822fa61 (contains the latest roll of Dart into teh engine). (#13269)

* Add a minimum distance that needs breaking on iOS each time scrolls stopped.

* Testing and tests

* tweak docs

* review

This is in preparation for adding a second card with a demo for animated
icons.

Table refactor is just a cleanup (that also fixes an alignment bug).

* Implements FlatButton debugFillDescription

* Fix doc comment

* Override debugFillProperties instead of debugFillDescription

* Remove child debug property

* Add capability to print engine dart sdk to flutter doctor

* First round of review comments

* second round of comments

* Final review comments

* Fixed typo in navigator.dart doc comments

* Added survey js to docs template

Add support for IOS_SIMULATOR_HOME environment variable in IOSSimulator.logFilePath

flutter_tools can be run on environments where the user's HOME directory
is not the root of the iOS simulators' configs. This change adds support
for such environments by allowing the caller to set the simulator root
directory via an environment variable.

In https://github.com/flutter/flutter/pull/13141 I updated the demo name
from 'Animated Images' to 'Animated images' before submitted, but did
not update the name in the smoketest and transitions_perf test.

Existing microbenchmarks task is extended instead of adding a new one to consume less horizontal space on Flutter dashboard.

This fills out the following matrix:

App: `flutter create` default app, Complex Layout, and Gallery.
Platforms: Linux/Android, Mac/iOS, Windows/Android
Build modes: full release, aot blobs, debug
Dart: normal, 2.0 preview

It also renames all the tests that used "build" to mean compilation
build to use "compile" instead, so that it's much clearer on the
dashboard.

Also, mark some flaky tests that are no longer flaky as not flaky.
Also, remove uses of call() since that's probably going to go away at
some point.

This consolidates all of the non-template .gitignore rules into the top level .gitignore, to ignore common things more broadly, with less maintenance needed for the .gitignore files. Does not touch the templates, so that they still produce needed .gitignores as part of flutter create.

* add an assert to validate the RefreshIndicator.onRefresh result

* add a test for RefreshIndicator.onRefresh assert

* switch to using FlutterError.reportError, FlutterErrorDetails, and FlutterError