This reverts commit e2490f29.

This reverts #76179 and relands #73042 with an active timer check fix.
Co-authored-by: David Reveman <reveman@google.com>

This reverts commit 9133deb9.

Timer based pointer event resampling

This provides two improvements to pointer event resampling:

1. PostFrameCallbacks are used instead of scheduling frames. This
avoids unnecessary rendering work when resampling is used.

2. Resampling continues when frames are not produced. I.e. input
events keep being delivered at a fixed frequency even if frame
production is taking a long time.

This fixes #72924
Co-authored-by: David Reveman <reveman@google.com>
Co-authored-by: Tong Mu <dkwingsmt@users.noreply.github.com>

This reverts usages of the binding's platformDispatcher to use window again temporarily, because there isn't a TestPlatformDispatcher yet, and so some tests were failing because they mocked the TestWindow to return certain things (locales) that were returning the real values instead of the test values.

Once I've created a TestPlatformDispatcher to allow fake data to be passed to it, we can go back to using the platformDispatcher in all of these places

Remove references to `Window`, and switch usages to `PlatformDispatcher` or `SingletonFlutterWindow` (#69617)

* Remove references to dart:ui.Window, and point usages to PlatformDispatcher or SingletonFlutterWindow, as appropriate

* remove new test platform dispatchers

* Amend documentation

* Improve resampling of up and remove events.

This improves resampling of these events by searching
for them until the next approximate sample time.
Co-authored-by: David Reveman <reveman@google.com>

move resampler to handlePointerEvent and fix complex_layout_android__scroll_smoothness with PointerEvent (#66745)

Expose GestureBinding.handlePointerEvent, replacing dispatchEvent as the preferred way to dispatch events (#64846)

* Redesigns the interface between MouseTracker and RendererBinding&RenderView.
* Simplifies the structure of RenderMouseRegion.
* Extracts the common utility code between mouse_tracker_test and mouse_tracker_cursor_test.

* add language version 2.8 in packages/flutter

* enable non-nullable analyzer flag

This normalizes all of the "See also" blocks in comments so that they conform in style.

They all look like this now:

  /// See also:
  ///
  ///  * [MyFavoriteWidget], because it's cool.
  class Foo {}

I removed some useless "See also" blocks, and added commentary to ones that were just "bare" references.

This is my penance for adding so many bullets that are "-" instead of "*". :-)

* 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

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

Adds support for discrete scroll events, such as those sent by a scroll wheel.

Includes the plumbing to convert, dispatch, and handle these events, as well as
Scrollable support for consuming them.

* add trailing commas on list/map/parameters

* add trailing commas on Invocation with nb of arg>1

* add commas for widget containing widgets

* add trailing commas if instantiation contains trailing comma

* revert bad change

This implements support for hovering mouse pointers, so that mice connected to Android devices, and ChromeOS devices running Android apps will work properly.

It teaches flutter_test about hover events, which required changing how they are created and used.

Also modifies AnnotatedRegion to allow a region that can be located someplace other than just the origin.

Along with tests for all of the above.

Fixes #5504

This re-lands 3c56e6c7 on top of a new Dart SDK that contains new mixin syntax fixes.

This reverts commit 3c56e6c7.

It breaks the AOT build.

* first pass

* revert WidgetsBindingObserver

* disable prefer_mixin

* docs and more mixins

* newer engine; binding fixes

* upgrade dependencies

* fix test binding

* remove whitespace

* remove the obsolete `enableSuperMixins: true`

* upgrade dartdoc to 0.22.0

* temporarily use git version of dartdoc

* fix pub global activate syntax

* use dartdoc 0.23.0

* enable lint unnecessary_new

* fix tests

* fix tests

* fix tests