[flutter tools] Add a DelegatingLogger class

Move most of `DelegateLogger` `from test/src/testbed.dart` to
`lib/src/base/logger.dart` to better formalize the common practice of
chaining `Logger`s together.  I renamed the class since it isn't
itself the delegate and to better match the `Delegating...` classes
from `package:collection`.

Additionally, add a freestanding `asLogger<T>` function to "cast" a
`Logger` into a matching delegate if possible.  This will allow
`Logger` chains to be ordered a *bit* more freely (e.g.
`NotifyingLogger` and `AppRunLogger` will no longer required to be
at the end of the chain, an unwritten rule that has led to breakage in
google3).  Chain order still matters since lack of virtual dispatch
means that parent `Logger`s can never invoke child methods, however.

I made `asLogger<T>` a freestanding function because I didn't want to
make it part of the `Logger` interface (and I thought that making it
an extension method might be weird).

Bonus cleanup:
There no longer appears to be a way to construct an `AppRunLogger`
with a null parent, so remove all of code paths for that case and
make the `parent` construction parameter required.

If the vm of an attached device rejects a hot reload, pretty print the reason. Suggest a hot restart so that users are aware that they do not have to detach and rebuild. Also resets the last compilation time, so a subsequent restart would still apply the last change. Adds an integration test for the const field removal.

Fixes #64027

The train command does nothing and was originally added to provide a no-output default for generating app-jit snapshots. The inject-plugins command is only for a repo-only analysis check, which is not necessary since we regenerate during pub get.

#29805

This reverts commit be5830cd.

This migrates more material tests to NNBD.

Reland "Flutter Driver - Create widget finders from serialized finders extensions" with null safety (#67711)

* Flutter Driver - Create widget finders from serialized finders extensions

[flutter_tools] remove globals from IntelliJ validator, refactor tests to remove dependency on JAR (#67240)

Move the intellij validator to its own file, and split off the tests. Remove globals from each, and remove dependency on a real jar/filesystem by creating a minimal version of the manifest xml and setting it up in the memory file system.

#47161

This reverts commit b33bfcef.

This reverts commit 3eb2335a.

Now that fast-start syncs assets by default, this isn't testing anything. Retire the test

Do not upload all assets on initial devFS sync. This should increase the reliability of the initial connection, even in the face of flaky devfs behavior, in addition to a moderate perf improvement.

Updates fast-start to build assets as part of the initial bundle

Requires flutter/engine#21436
Requires flutter/engine#21586
Requires flutter/engine#21611

* adding tests that uses integration_test (e2e) package to flutter

* change the package name for the import

* fix licenses. fix README commands. add links

* adding dependency change auto generated by the tool

* more analyzer error fixes

* Add tristate to parent checkbox for DataTable to follow Material specifications

* Add decoration parameter to DataTable and DataTableTheme

Revert "Flutter Driver - Create widget finders from serialized finders extensions (#67456)" (#67687)

This reverts commit 74f6fa45.

This converts the packages/flutter/test/services directory to NNBD, now that the services package is converted.

I changed the signature of checkMessageHandler and checkMockMessageHandler on BinaryMessenger to take a nullable handler, since the tests wanted to check to make sure a handler wasn't set, and that functionality no longer works if the handler is non-nullable.

* [flutter_tools] enable LocalDevFSWriter for desktop devices, iOS simulator

* Update device.dart

* Update desktop_device_test.dart

* fix analysis errors

We used to use zip to verify the integrity of downloaded zip archives, but we now use unzip. This removes the .zip method from OperatingSystemUtils.