In the event that no Dart VM's exist or are connectable, will instead
await for a new Dart VM to show up. Will no longer return null when
calling `getMainIsolatesByPattern`, instead returning either a list of
isolates or timing out.

It was causing problems rolling Flutter into Fuchsia

* re-enable lint unnecessary_const

* remove trailling whitespaces

* remove unnecessary const (after merge)

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

This reverts commit cc1cf13e.

Before a severe log would be raised when timeout happens. Now that
testing connections requires potentially running into a timeout, this
will cause failures when there shouldn't be any.

This prevents the error:

`type 'List<dynamic>' is not a subtype of type 'List<Map<String, dynamic>>' `

The test added fails when dart_vm.dart is reverted to `master`, and succeeds in
its current state.  This issue was run into while connecting to the
Dart VM.

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)

Similar to the flutter driver, now the fuchsia_remote_debug_protocol can
connect via an environment variable. This can also be used to point to
the SSH config location.

This makes it so that tests written using the FRDB do not have to write
extra information about where their device is on the network.

Now that Dart 1 is turned off, reapplying my change to turn on the prefer_generic_function_type_aliases analysis option, and fix all the typedefs to Dart 2 preferred syntax.

Also eliminated the unused analysis_options_repo.yaml file and turned on public_member_api_docs in analysys_options.yaml.

No logic changes, just changing the typedef syntax for all typedefs, and updating analysis options.

Revert "Update typedef syntax to use Function notation and turn on lint for old notation. (#18035)" (#18041)

This reverts commit 32586020.

Fixes #18028

Just changes typedef declarations, no logic changes.

This fixes a runtime error triggered when calling `invokeRpc`:
```
type 'Future<dynamic>' is not a subtype of type 'Future<Map<String, dynamic>>'
```

Also adds a log message for why connections are failing, as well as a
default timeout when attempting to connect to a websocket.

The new values are not ready for use yet inside Google

* Roll engine to e976be13c51448f89107d082ec81e2b6731671fa

* move away from deprecated constants

This change adds Dart VM event support (listening for when a VM starts/stops by using a periodic heartbeat).

This also adds support to connect to a specific `IsolateRef` through the flutter driver, so that when an application spawns, it can immediately be driven (as shown in included example code).

When forwarding all ports, run a test connection to each Dart VM instance, stopping port forwarding if the connection fails.

Also does the same for any batched calls that hit all Dart VM instances.

* [fuchsia] Pass a dummy command to the ssh tunnel setup

* Address analyzer lint

* Update fuchsia_remote_debug_protocol

* Handle error count reported by frontend.

Extend compilation result from single string to a structure(string filename and integer error count).

* Use ?.

* Include engine roll with dart sdk roll.

* parse(onError) -> tryParse

* Make '?? throw' more readable and avoid issue with analyzer

* Fix test so it mocks compiler output including errors count

Adds a package that will support connecting to and debugging devices with multiple instances of the Dart VM, and operate on multiple Isolates and Flutter Views.

Currently supports connecting to all existing Dart VMs and extracting information about all Flutter Views running across each VM.