This reverts commit c59151b1.

* Update project.pbxproj files to say Flutter rather than Chromium

Also, the templates now have an empty organization so that we don't cause people to give their apps a Flutter copyright.

* Update the copyright notice checker to require a standard notice on all files

* Update copyrights on Dart files. (This was a mechanical commit.)

* Fix weird license headers on Dart files that deviate from our conventions; relicense Shrine.

Some were already marked "The Flutter Authors", not clear why. Their
dates have been normalized. Some were missing the blank line after the
license. Some were randomly different in trivial ways for no apparent
reason (e.g. missing the trailing period).

* Clean up the copyrights in non-Dart files. (Manual edits.)

Also, make sure templates don't have copyrights.

* Fix some more ORGANIZATIONNAMEs

This fixes the mouse hover code to not schedule frames with every mouse move.

Before this, it would schedule a post frame callback, and then schedule a frame immediately, even if there was nothing that needed to be updated. Now it will schedule checks for mouse position updates synchronously, unless there's a new annotation, and skip scheduling a new frame in all cases. It has to be async in the case of a new annotation (i.e. a new MouseRegion is added), since when the annotation is added, it hasn't yet painted, and it can't hit test against the new layer until after the paint, so in that case it schedules a post frame callback, but since it's already building a frame when it does that, it doesn't need to schedule a frame.

The code also used to do mouse position checks for all mice if only one mouse changed position. I fixed this part too, so that it will only check position for the mouse that changed.

There were four or five different implementations in various tests for sendFakeKeyEvent, which roughly all did the same thing. I was going to add yet another one, and decided that it needed to be generalized and centralized. This replaces those instances with something that just takes a LogicalKeyboardKey so that it's self-documenting, and can be used with multiple platforms.

This adds two functions to widget tester: sendKeyDownEvent and sendKeyUpEvent which simulate key up/down from a physical keyboard. It also adds global functions simulateKeyDownEvent and simulateKeyUpEvent that can be called without a widget tester. All are async functions protected by the async guard.

* Moved the default BinaryMessenger instance to ServicesBinding

This reverts commit 821602ae.

* Added assertion in defaultBinaryMessenger. Also fixed the devicelab tests.

Flutter widget tests assert if a test completes with timers still
pending.  However, it can be hard to diagnose where a pending timer
came from.  For example, a widget might consume a third-party library
that internally uses a timer.

I added a FakeAsync.pendingTimersDebugInfo getter to quiver
(https://github.com/google/quiver-dart/pull/500).  Make flutter_test
use it.

Additionally modify Flutter's debugPrintStack to take an optional
StackTrace argument instead of always printing StackTrace.current.

Fixes #4237.

* Broadcasting popRoute and pushRoute methods via SystemChannels.navigation. These messages will be used in flutter_web to detect the route

* Broadcasting popRoute and pushRoute methods via SystemChannels.navigation. These messages will be used in flutter_web to detect the route

* Reverting all unrelated formatting changes.

* Adding unit tests. Adding more comments.

* Changing string method names with constant strings.

* Fixing a constant strings.

* Fixing analyzer error.

* Fixing more white space.

* Changing the method names. Adding comments to the SystemChannels

* Comment and code name fixes

* replacing the comment with reviewer suggestion.

* addinf systemchannels.navigation mock to test bindings

* Adding a new class for sending route change notrifications. The nottifications are only sent on web. This should fix breaking android/ios

* using new class RouteNotificationMessages in navigator

* Fixing analyzer issues.

* fixing cycle dependency

* fixing github analyze error

* dartfmt two new classes. trying to fix anayze errors

* Update route_notification_messages.dart

* trying to fix white space errors

This reverts commit 92ef2b9c.

This requires either runApp() or
WidgetsFlutterBinding.ensureInitialized() to have been called before
using any MethodChannels. Plugins broadly rely on MethodChannels and
right now there's no general requirements that they be constructed
within the runApp call, so the ecosystem breakages from this are broader
than originally thought. Reverting for now.

* more ui-as-code

* address review comments

* Make it possible to override the FLUTTER_TEST env variable without unsetting it.

* Switch to using platform instead of Platform.

* Document the bindings, and introduce tests that initialize multiple WidgetsBindings with different environments.

* Add tests for the flutter platform test.

* Add license headers

* Fix lints

* Remove trailing whitespace

* Respond to Jonahs comments

* Respond to Ians comments

* Mock out the HttpServer in flutter_platform_test

* Mock out the HttpServer in flutter_platform_test

* Explain why we mock out the HttpServer in flutter_platform_test

Follow-on change to https://github.com/flutter/flutter/pull/34863 (see that change
for context), whereby we ensure that we're properly dealing in `Uint8List`.

These necessary changes would have been caught by disabling implicit casts
in our analysis options.

dart-lang/sdk#36900
https://github.com/flutter/flutter/issues/13815

* Prepare for HttpClientResponse Uint8List SDK change

An upcoming change in the Dart SDK will change `HttpClientResponse`
from implementing `Stream<List<int>>` to instead implement
`Stream<Uint8List>`.

This forwards-compatible change to `_MockHttpClientResponse` is being
made to allow for a smooth rollout of that SDK breaking change. The
current structure of the class is as follows:

```dart
_MockHttpClientResponse extends Stream<List<int>> implements HttpClientResponse {
  ...
}
```

This structure would require that the Dart SDK change land atomically
a change to the class (`extends Stream<Uint8List>`). This atomic landing
requirement doesn't play well at all with Flutter's roll model vis-a-vis
the Dart SDK's roll model to Google's internal repo.  As such, this commit
changes the structure of `_MockHttpClientResponse` to be:

```dart
_MockHttpClientResponse implements HttpClientResponse {
  final Stream<Uint8List> _delegate;

  ...
}
```

Once the Dart SDK change has fully rolled out, we can simplify this class
back to its former structure.

https://github.com/dart-lang/sdk/issues/36900

* Review comment

This re-applies the changes that were made in #33697 and #33729,
but which were reverted in #33792 and #33790, respectively due to
the Dart SDK not having received the update within Google yet.
The SDK has now rolled, so these changes can be re-applied.

https://github.com/flutter/flutter/issues/32374
https://github.com/flutter/flutter/issues/33791

https://github.com/flutter/flutter/issues/33791

https://github.com/flutter/engine/compare/69ebe5fb28fc..68a3ca46b40a

git log 69ebe5fb28fca271b23010d43d4dc7f6e5286c4f..a4b7d1c2895d82228705a021cdb7fdb2f71ac2a5 --no-merges --oneline
4c6253cdd Copy the macOS podspec during builds (#9158)
68a3ca46b Roll src/third_party/dart 445a23a9bc..0e6b74543c (29 commits) (#9159)
1d1cff1fa Roll src/third_party/skia 3cd435eecf5e..09f5aedf2cc8 (3 commits) (#9160)

The AutoRoll server is located here: https://autoroll.skia.org/r/flutter-engine-flutter-autoroll

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+/master/autoroll/README.md

If the roll is causing failures, please contact the current sheriff (cbracken@google.com), and stop
the roller if necessary.

* Deprecates `BinaryMessages` in favor of a default instance of `BinaryMessenger`, called `defaultBinaryMessenger`
* Platform channels use the `defaultBinaryMessenger` for their binaryMessenger default argument.

https://github.com/dart-lang/sdk/issues/36971

This fixes #32525, because it now marks the compositing bits as needing to be recalculated if the mouse tracker changes its idea of whether or not a mouse is attached.

This bug occurred because the test framework was leaking state from one test to the next (the state about whether a mouse pointer was active), and so even though there was a "passing" test when run in order with the other tests in the file, when the test was run individually (or first), it would have failed and caught the bug.

This adds an assert to make sure that after each test there are no simulated mouse pointers connected, and now calls removePointer in all of the tests where this was a problem.

Make FlutterError objects more structured so they can be displayed better in debugging tools such as Dart DevTools.

This re-lands the Focus changes in #30040. Correctness changes in routes.dart, and removes the automatic requesting of focus on reparent when there is no current focus, which caused undesirable selections.

Addresses #11344, #1608, #13264, and #1678
Fixes #30084
Fixes #26704

Previously benchmark_test.dart would break if run with --update-goldens.
Now the entire test suite can be run with --update-goldens.

This reverts commit 4218c0bc.