Pull in new versions of packages with fixes for SCREAMING CAPS CONSTANTS.

Our Cirrus Windows tests were not really working: they reported success even when failing.

This should fix several problems with the Cirrus Windows tests.

* Fix the checksum verification to be more sensitive

* update packages

This uses @kevmoo's completion package to do command line completion for flutter, and a new command "bash-completion" (with alias "zsh-completion") that will output the necessary shell script setup code, and adds the hidden command "completion" that does the actual completion.

Because it adds a dependency, I also had to do flutter update-packages --force-upgrade.

Fixes #18988.

Revert "Revert "Roll engine to fed2ea458ed49088d33eddabc546ba56d600c717 (includes dart roll) again (#19277)" (#19295)" (#19322)

This reverts commit cc122f16.

Revert "Roll engine to fed2ea458ed49088d33eddabc546ba56d600c717 (includes dart roll) again (#19277)" (#19295)

This reverts commit 700cb767 as it
breaks Windows tests.

* Revert "Revert "Roll engine to fed2ea458ed49088d33eddabc546ba56d600c717 (includes dart roll) (#19044)" (#19276)"

This reverts commit cf932490 as it also
includes fix for type error that broke tests.

* Add type cast for dart2 type checks.

* Move up to latest goldens

* Make inDirectory() type-parameterized.

* Add typecasting to transitions_perf_test.dart and microbenchmarks.

* Add boolean flag initialization in save_catalog_screenshots.dart

* Add type conversion to gallery transition test

Revert "Roll engine to fed2ea458ed49088d33eddabc546ba56d600c717 (includes dart roll) (#19044)" (#19276)

This reverts commit f4a038da as it breaks microbenchmark tests.

* Roll engine to rolled dart
Add connectionTimeout property to class that extends HttpOverrides.
Upgrade packages.
Add more type fixes.
Update goldens hash.
Add more type fixes.
Upgrade packages.
Fix tests.
Remove strong-mode from analysis options yaml file.
Increase dev/devicelab timeout from 2 to 10 seconds.
Added getVM to waitForViews. Fix type errors in compileExpression.

* Pick up engine revision with fix for microbenchmarks regression.
Increase default timeout from 20/30 to 60s.

* Bump mockito to 3.0.0-beta

* Few fixes

* fix test

* Bump image

* Fix

* New packages update

* With matcher pinned

* No more typed

The new matcher package deprecates isInstanceOf which seems eggregious.

This reverts commit e593dc70.

"flutter update-packages --force-upgrade"

* no longer use the analyzer version shipped in the sdk

* update all package versions to the latest

In order to avoid checking binaries into flutter/flutter,
this comparator can be used to retrieve golden files from
a sibling flutter/goldens repository.

https://github.com/flutter/flutter/issues/16859

* Bump mockito to 3.0.0-alpha+3

* Type annotation

Switch to the new Matrix4.tryInvert method to avoid throwing and catching (#15771) exceptions while performing hit testing.

* re-enable verify-only failing test for out of sync deps and update deps to latest version

* Revert "Revert "Move mockito to 3.0.0-alpha. (#15949)" (#15979)"

This reverts commit e59651f9.

* More thenReturn to thenAnswer when mocking Futures

* Revert "More thenReturn to thenAnswer when mocking Futures"

This reverts commit 194d2cf41754ad171efd6bb5898cf73bce5a75ab as we are reverting engine roll.

* Revert "Revert "More thenReturn to thenAnswer when mocking Futures""

This reverts commit 52c9e96b304b220f66d78a252fccea0c8e0ef24c.

* Add dependency override

* Fix issue

This reverts commit a7e62258 as there are failing tests.

* Move mockito to 3.0.0-alpha.

This is needed so it matches mockito version used internally.

* Pick up +2 for the fixes

* Fix whenReturn in fuchsia_remote_debug_protocol

* more thenReturn becomes thenAnswer

* more thenReturn becomes thenAnswer

* more thenReturn becomes thenAnswer

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.

* use HttpOverrides and dart:io HttpClient in flutter

* add missing package:http dependency

* update flutter packages and remove comment about createHttpClient from flutter_test

* move byte loading logic to common class, move string parsing logic to base class

* addAll doesn't work for a Uint8List

* use bytes.setRange

* undo addition to hello_world

* add newline to end of binding.dart

* and a newline for hello world

* refactor to function and add tests

* address comments on unknown length case

* alignment

* sort alaphabetically

* rename convertResponse to consolidateClientHttpClientResponseBytes.  Add header

* fix alignment in test

* traverse dependencies and dev dependencies separately

* separate dev and reg deps

* update pubspecs

* add checksum string and update transitive dep string.  Add additional verify command to check checksum

* cleanup comments

* add missing space, quote, run verify-onlu from bot script

* rerun tool with fixed string

* ensure correct working directory and bump versions

* flutter not flutterRoot

This fixes https://github.com/flutter/flutter/issues/15458.

* Update dependencies with forced upgrade.

Now that https://github.com/flutter/flutter/issues/15261 is fixed, do the update with upgrade.

* Update test package use following upgrade

* Replace addOption(allowMultiple) with addMultiOption

This is needed to fix 'flutter test --preview-dart-2 test/all.dart' in dev/devicelab

30+4 has made some changes to the remoting protocol that are incompatbile
with a test harness running 30+3 (e.g. adding a type='initial' field to the
first message)

* Use engine-built dart sdk

* Download dart-sdk from engine

* Move up deps to fix dart sdk constraint problem

* Update update_dart_sdk.ps1 for Windows

* Fix tests so they pass analysis

* More types for tests

* Roll engine

* Update dart sdk stamp location in flutter.bat

* Add newline

We need to pull in Dart 2 compliant mockito

Fixes #14532

There were some problems I introduced with the last PR for this. It passed the test, but failed in practice.

This adds tests for those failure cases, adds a "--help" and fixes the test so that it doesn't try and actually download MinGit as part of the Windows test.

I added package:platform as a dependency, so I did a force upgrade on the packages.

Also, re-enabling 'create package' in the cache warming code, now that #14448 is fixed.