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.

Stop building (unused) unlinked summaries for packages.

Improves update speed considerably (for `n` packages it saves us `n` needless calls to `pub get`).

* Update to Dart SDK `1.22.0-dev.6.0`.

* Update SDK summary generation to create spec and strong summaries.

* Updated to dev.8.0.

* Fixed console out.

This reverts commit ef25a203 to unbreak the build.

* Bump Dart SDK to 1.22.0-dev.5.0.

* Suppress spurious `FutureOr` type warning.

* Fixed linter dep post merge.

* Formatting tweaks.

This ensures that accidental usages of dart:io's
file API don't creep in over time.

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.

- [x] Introduce DependencyChecker which can determine if any dependencies have been modified.
- [x] Move the DartDependencyBuilder into a separate file.
- [x] Add unit tests for DartDependencyBuilder.
- [x] Add unit tets for DependencyChecker

Part of #7014 

* convert pubGet to throw ToolExit on non-zero exit code
* convert commandValidator to throw ToolExit for non-zero exit code
* convert flutter commands to throw ToolExit for non-zero exit code
* use convenience method throwToolExit
* only show "if this problem persists" for unusual exceptions

I was in here trying to figure out why we rebuild sky_services (the
answer is, because we rebuild every package we've ever downloaded, but
that's not really a problem for new users so whatever), and while I
was here I did some cleanup.

* make showElapsedTime default to true

* support nested progresses

* improve hot reload message

* rethrow

Fixes #6417

These aren't needed anymore.

Bump to latest Dart SDK dev build (`1.21.0-dev.0.0`).

* updates to analyzer w/ support for bazel workspaces
* removes deprecated analysis `cacheSize` variable access

* Bump Dart SDK to `1.20.0-dev.10.0`.

`1.20.0-dev.10.0` corresponds to `1.20-RC0`.

* pubspec.lock cleanup

* check for pubspec.lock existence

* cleaned up conditional remove

* suppress warning; decouple the analyzer versions

* also pass in --no-packages-dir

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.

* Roll to Dart SDK `1.20.0-dev.5.0`.

* bumps to `1.20.0-dev.5.0`.
* updates `analyzer` API use.

* Add explicit types.

* Build unlinked summaries for packages on upgrade.

* Iterate through the packages in folders.

* Rollback the debug change.

* Udpate to Dart `1.20.0-dev.1.0`.

Udpate to Dart `1.20.0-dev.1.0` and corresponding `analyzer` package.

* Added `--no-packages-dir`.

* Revert extension to master.

* Added ignores.

* Review nits.

* More nits.

* Build sky_engine Dart SDK summary bundle on FlutterEngine.download().

* Tweaks for Devon comments.

* Tweaks for Phil comments.

* make flutter run work with a pre-built apk

* refactor to remove the buildDir param

This makes the about page show the licenses of all the Dart packages that a Flutter app uses.

Issues that this does not yet resolve:
- I'm still working on getting the full list of licenses for the sky_engine package.
- Some of the licenses don't print very readably.
- There's no scrollbar on the license page.

I'll provide fixes for the first two in the coming days, but this should unblock anyone who is wanting to see something here, even if it's not quite complete. :-)

----

The patch makes the following changes: 

- The license registry is now asynchronous, since the data comes from disk.
- I moved the default license collector from the foundation package to the services package since it uses the default asset bundle now.
- The FLX builder now includes the LICENSE files of each Dart package mentioned in the `.packages` file.

* brings in analyzer version (`0.27.4-alpha.14`) corresponding to current Dart SDK (`1.18.0-dev.2.0`).
* updates analysis to use prefered API for embedder URI resolution
* adds trampolines to `State` and `StatelessWidget` to allow for warning-free within-library @protected access (needed since we closed off access to @protected closures from outside subclasses).
* turns off cache dependency tracking for analysis (in DDC this amounted to a 10% speed improvement).

* refactor the --resident run option into a separate file

* update daemon to run --resident apps

* re-plumbing daemon start

* send app logs

* update tests

* review changes

* fix test runner

* remove PackageMap.createGlobalInstance; rely on the ctor

* review comments

Cleans up 3 of the 4 violations of the `overriden_field` lint.

The last one is more interesting and I'll defer to someone closer to that code:

    [lint] Do not override fields. (packages/flutter/test/rendering/rendering_tester.dart, line 91, col 14)

Net-net: SDK summaries are not safe in the presence of SDK library embedders.

Context (and bug to track re-enablement) here: https://github.com/dart-lang/sdk/issues/26467.

* use vendored dart sdk; check the expected version of flutter

* search up directories looking for the flutter root