* Remove uses of deprecated constants
* Change int.parse to int.tryParse where appropriate

fuchsia_tester.dart still assumes Dart 1. Previously, it ran tests directly
from source, flutter_platform.dart automatically runs a kernel compile when
operating in Dart 2 mode, but this assumes a functional Dart SDK is available
in the artifacts directly, and fuchsia_tester.dart mocks out the artifacts
directory with an empty temp dir.

Remaining work is:
1. Get the frontend server building as a dependency on Fuchsia.
2. Patch fuchsia_tester.dart to use a valid Dart SDK and frontend server.

This also reverts migration to Dart 2 typedef syntax.

This reverts commit 6c56bb24. (#18362)
This reverts commit 3daebd05. (#18316)

* It's time to #deleteDart1 (#18293)

Eliminates support for Dart 1 in flutter_tools, and drops our Dart 1
benchmarks. All commands now run in Dart 1 mode only.

Eliminates --preview-dart-2 / --no-preview-dart-2 support.

* Fix indentation, remove no longer necessary .toList()

* Only push udpated kernel if >0 invalidated srcs

Several benchmarks started failing during kernel compile:
1. Timeouts:
   * commands_test
   * hot_mode_dev_cycle__benchmark
   * run_machine_concurrent_hot_reload
   * service_extensions_test

2. Kernel compiler crash:
   * hot_mode_dev_cycle_linux__benchmark
   * routing_test

3. Unexpected termination:
   * hot_mode_dev_cycle_win__benchmark

This reverts commit ed63e708.

Eliminates support for Dart 1 in flutter_tools, and drops our Dart 1
benchmarks. All commands now run in Dart 1 mode only.

Eliminates --preview-dart-2 / --no-preview-dart-2 support.

The non-deprecated variants aren't widely available yet

re-write flutter analyze (the single-shot and --flutter-repo) to use the analysis server

Revert "re-write flutter analyze (the single-shot and --flutter-repo) to use the analysis server (#16281)" (#16482)

This reverts commit 2f41ea54.

re-write flutter analyze (the single-shot and --flutter-repo) to use the analysis server

* roll engine version to 6280adbfb1f9f63cdc6179b9b78634add1e4f2e3

* Correctly handle previewDart : false setting in AnalysisServer and
AnalyzeOnce classes.

* have flutter analyze support --preview-dart-2

* review comments

This reverts commit e13e7806.

Turns out that with this patch, we aren't actually catching all
errors. For example, `flutter analyze --flutter-repo --watch` didn't
report errors in `dev/devicelab/test/adb_test.dart`.

* flutter analyze --watch auto detect if in flutter repo
* move isFlutterLibrary from AnalyzeOnce into AnalyzeBase for use by AnalyzeContinuously
* pass --flutter-repo to analysis server when analyzing the flutter repository
* enhance flutter analyze --watch to summarize public members lacking documentation

* Bump to Dart SDK 1.24.0-dev.6.7.

* nits and fixes

* move flutter user analysis options file
* add comments referencing each of the analysis options files

See https://github.com/dart-lang/sdk/issues/28463, which I think is a
regression.

This also fixes the regression introduced by
https://codereview.chromium.org/2559773002 whereby we were no longer
checking any of the lints.

This removes direct file access from within flutter_tools
in favor of using `package:file` via a `FileSystem` that's
accessed via the `ApplicationContext`.

This lays the groundwork for us to be able to easily swap
out the underlying file system when running Flutter tools,
which will be used to provide a record/replay file system,
analogous to what we have for process invocations.

* Remove the workaround that pinned args to v0.13.6
This reverts most of the changes in commit 6331b6c8
* throw exception if exit code is not an integer
* rework command infrastructure to throw ToolExit when non-zero exitCode
* convert commands to return Future<Null>
* cleanup remaining commands to use throwToolExit for non-zero exit code
* remove isUnusual exception message
* add type annotations for updated args package

* convert flutter commands to use ToolExit for non-zero exit code
* add convenience method throwToolExit
* print ToolExit message iff not null

* show hidden flags when showing verbose help
* flutter -v show verbose help

This rewrites imports of various mojom.dart files from the Flutter
engine repo to instead import normal-looking dart files from the
(new) flutter_services package. This package handles exporting the
correct symbols from generated code wherever that may live.

Includes an engine roll to 3551e7a48e2e336777b15c7637af92fd7605b6c5
which contains the new flutter_services package.

* Update tools to use `analyzer` from vended Dart SDK.

* updates `flutter_tools` and `flutter_test` to use the SDK-vended `analyzer` package
* tweaks dependency tracking logic to only record the SDK-vended `analyzer` so as not to crash on spurious conflicts (due to transitive dependencies)

* Review fixes.

* refactor _run to runCmd

* replace requiresProjectRoot getter with call to commandValidator

* replace requiresDevice getter with call to findTargetDevice

* trace command requires a debug connection, not a device

* inline androidOnly getter

* rename command methods to verifyTheRunCmd and runCmd

* move common verification into BuildSubCommand

* rename deviceForCommand to device

* rename methods to verifyThenRunCommand and runCommand

This moves all of the various .analysis_options* files to the flutter repo root so that it's easier to
* remember to keep them all in sync, and
* easily refer customers to them

part of https://github.com/flutter/flutter/issues/5789

This updates the flutter analyze command to use the .analysis_options_flutter_analyze in the repo root when either the --flutter-repo flag is supplied or the sources being analyzed reside in the flutter repo.

#4672