* Clean up some flutter_tools tests
* Remove arbitrary retry that happens even for fundamental errors, and generally clean up _DevFSHttpWriter.
* Update dependencies (requires fixes; see next commit)
* Fixes for new dependencies.
Adds a Fuchsia compatibility function that allows for connecting to a
specific Isolate by name when running Flutter Driver on a Fuchsia
device. This will check over multiple Dart VM's in an attempt to find
an Isolate by its name.
flutter_tools cannot depend on flutter_goldens (as flutter_goldens
depdends on the Flutter sdk), so this commit splits client.dart from
flutter_goldens to a pure-dart flutter_goldens_client package.
* Reland "Roll engine to version b148e628ec86b3a9a0382e0bcfae73f0390a8232 (#20427)"
This is a re-land with downgraded `package:flutter_gallery_assets`
version.
* Downgrade package:flutter_gallery_assets to 0.1.4
* Change engine.version to 81baff97c29bb08cbf8453a3f9042c5813f84ad3 (which contains an additional fix)
* Change engine.version to e3687f70c7ece72000b32ee1b3c02755ba5361ac (since mac tarballs are corrupted on earlier commit)
Reason for revert: The package:flutter_gallery_assets has removed some images which are required for the examples/flutter_gallery, so the gallery build is failing (only discovered after landing, since gallery doesn't seem to get built during github PR presubmit checks)
This CL
* rolls `engine.version` to flutter/engine@b148e628 (which includes dart sdk 2.1.0-dev)
* rolls `goldens.version` to flutter/goldens@6c45fafdf (which includes updates due to skia changes in engine)
* changes `platform.dill` to `platform_strong.dill` in various places due to flutter/engine@a84b210b
* adds explicit `environment: sdk: ">=2.0.0-dev.68 < 3.0.0"` constraints to `pubspec.yaml` and `pubspec.yaml.tmpl` files (since pub defaults to `<2.0.0` if omitted)
* upgrades to newer versions of various 3rd party packages (to ensure transitive dependencies have `<3.0.0` sdk constraint)
* Upgrade everything except matcher.
* Roll matcher (and test)
* Adjust tests that depend on flutter:test directly to depend on a shim
* Require use of package:test shim and remove other references to package:test
Our Cirrus Windows tests were not really working: they reported success even when failing.
This should fix several problems with the Cirrus Windows tests.
