* Test gradle dependency file generation

* Fix lints, clean up comments, formatting.

* Fix `flutter test --preview-dart-2`  following last dart roll.

Incremental compiler maintains single incremental dill file, so for every test compilation that dill file has to be copied away for execution.

* Fix lints

* Fix some of the generic types specified to avoid runtime errors in
--preview-dart-2

  type 'YamlMap' is not a subtype of type 'Map<String, dynamic>' where
    YamlMap is from package:yaml/src/yaml_node.dart
    Map is from dart:core
    String is from dart:core

  package:flutter_devicelab/framework/manifest.dart 17:36       loadTaskManifest
  test/manifest_test.dart 14:33                                 main.<fn>.<fn>
  package:test/src/backend/declarer.dart 161:27                 Declarer.test.<fn>.<fn>.<fn>

* Add dynamic generic types to keep the analyer happy.

* Address code review comment.

* spelling: accommodate

* spelling: allotted

* spelling: anonymous

* spelling: artificial

* spelling: associated

* spelling: asset

* spelling: button

* spelling: canvas

* spelling: compatibility

* spelling: coverage

* spelling: condition

* spelling: decoration

* spelling: deferring

* spelling: diameter

* spelling: direction

* spelling: displacement

* spelling: dropdown

* spelling: needing

* spelling: environment

* spelling: exited

* spelling: expansion

* spelling: explore

* spelling: families

* spelling: horizontal

* spelling: increment

* spelling: indices

* spelling: internationalization

* spelling: labrador

* spelling: localizations

* spelling: midflight

* spelling: milliseconds

* spelling: minimum

* spelling: multiple

* spelling: multiplication

* spelling: navigator

* spelling: overridden

* spelling: package

* spelling: performance

* spelling: platform

* spelling: porsche

* spelling: position

* spelling: preceded

* spelling: precede

* spelling: precedence

* spelling: print

* spelling: property

* spelling: readily

* spelling: reproducibility

* spelling: rounded

* spelling: scroll

* spelling: separate

* spelling: separator

* spelling: services

* spelling: specific

* spelling: specify

* spelling: synchronously

* spelling: through

* spelling: timeout

* spelling: triangle

* spelling: trivial

* spelling: unusual

* spelling: then

* spelling: vertically

* spelling: visible

* spelling: visited

* spelling: voice

* Pass entry points JSON files to front-end server (#15180)

* Fix ios/debug build which uses 'flutter build aot': do not require entry points files and disable AOT transformations in this mode

* Revert "Pass entry points JSON files to front-end server (#15180)"

This reverts commit 0edea887.

Reason: buildbot failures on Mac.

* Add selection haptic feedback to Cupertino Pickers

* review

* don't haptic on android

* Add to Artifacts, and add optional arguments to entry points for flut… (#15185)

Add to Artifacts, and add optional arguments to entry points for flutter run and test to allow for wiring up the same with preview-dart-2 internally

* Changing packages uri here is not necessary

* Add a test that measures/verifies start from warm state(app was previously compiled).

* Remove json file from the first run.

This reverts commit e0f6e626.

Add to Artifacts, and add optional arguments to entry points for flutter run and test to allow for wiring up the same with preview-dart-2 internally

Pass extra front-end and gen_snapshot options to GenerateDependencies gradle task, as it also runs 'flutter build aot' (#14980)

https://github.com/dart-lang/pub/issues/1812

* [semantics]: minor docs & style clean-up

* remove a

* add a debug check that the returned Type of State.initState and State.didUpdateWidget are not Futures

* add test to verify that async lifecycles throw FlutterErrors

* address some feedback, match implementation of setState check

* address feedback from hixie

* fix odd spacing in test

* Run dev/bots/test's flutter drive test in preview-dart-2

* Fix extension callback type

* More type fixes

Fixes https://github.com/flutter/flutter/issues/15136

Someone ended up with STAMP_PATH containing a blank line.

Also, replace [ with [[.

* [tools] consolidate "preview Dart 2" option in BuildInfo

* format BuildInfo constructor

Document missing value types supported by `within`. Add missing tests. Simplify _sizeDistance implementation.

when a hot reload is done after modifying a component in the flutter
package.

* Use depfile in --preview-dart-2 mode.

* Generate and use frontend_server.d to guard against reusing outdated dill files when frontend_server changes.

Changes since last roll:
  - Leave only widget creation tracker kernel pass in flutter frontend server. (#4727).

* Roll engine to c88ba37c794f57982374bb53a694301198cad593.

Changes since last roll:
  - move generated entry points JSON out of flutter_patched_sdk
  - List missing core lib bigint_patch.dart source for new Bigint implementation (#4735)
  - Skip over .emf-files. (#4739)
  - Roll dart to ee15c8eb689791f6777eb3f6b0a1e9c58ff0671b.

* defaultValue -> orElse

Orientation, and by extension time for rotation between orientations,
was aspirational and never used.

While this is technically a breaking change, this code never actually
did anything. If you were setting either orientation or timeForRotation,
simply delete those parameters and the code will continue to behave
identically to how it had been.

Fixes a small rendering problem when dragging the slider, as well as a couple of small bugs (de-duping of value changes, and actually using a parameter passed to _unlerp).

Includes:
* Add nil check for country code and language code (flutter/engine#4732)