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.

This reverts commit 6ad88bd5.

* Fixing LocalFileComparator output

* Fixing path separators for windows failures

* Windows path issues

* Testing

* ++

* ++

* Fixing base directory - windows

* Clean up

* Minor improvements to framework documentation.

* maybePop documentation fix

* Mark some flutter_test arguments required.

Without these set, we get a crash.

* Minor correction to ListView docs

This reverts commit 6ef80b44.

This is the continuation of https://github.com/flutter/engine/pull/11041 and https://github.com/flutter/flutter/pull/38574

This is not a breaking change as we're not removing `onReportTimings` API.
We're simply removing the use of it in our framework.

* Wire Window.systemGestureInsets to MediaQuery.systemGestureInsets

* Add systemGestureInsets property to TestWindow

* 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.

Filed: https://github.com/flutter/flutter/issues/38838
to track these usages.

This was introduced by: https://github.com/flutter/engine/pull/11041

Teach Layer and its implementations, RenderObject and its implementations, and PaintingContext to reuse engine layers. The idea is that a concrete RenderObject creates a Layer and holds on to it as long as it needs it (i.e. when it is composited, and the layer type does not change). In return, each Layer object holds on to an EngineLayer and reports it to the engine via addRetained and oldLayer. This allows the Web engine to reuse DOM elements across frames. Without it, each frame drops all previously rendered HTML and regenerates it from scratch.

* 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.

This reverts commit 3a2d3081.

This reverts commit eb0b1790.
Skia Gold post-submit test were failing due to the service account not being found on Cirrus.

* Fresh PR for Gold integration.

* Nits

* WIP

* Artifacts from merge

* Changed some platform dependencies for web, added library prefix notation for Skia Gold test names.

* Updating for CI implementation

* Write out service account

* Writing to skip out

* WIP

* ++

* Fixing depot tools deps

* Windows depot_tools

* Fixing setup scripts

* ++

* depot tools

* ++

* WIP

* Tracing depot_tools clone

* WIP

* ++

* analyzer

* WIP

* chrome typo

* copy artifact

* Working on tests

* Code cleanup

* ++

* Code cleanup, updated tests

* ++ review feedback

* Review

* Analyzer

* Review feedback

* Nits from review

* PRogress

* ++

* Fixing tests

* ++

* Testing repo route

* Just needing documention around new structures.

* cleanup

* Analyzer

* Documentation updates

* Documentation updates

* Cirrus updates

* cirrus nit

* Review feedback

* Review feedback

* Fixing skip comparator

* Fix base directory for Skia Gold case

* ++

* Feedback

* ++

* Fixed uri assertion

* Made GoldensClient abstract, altered SkiaGoldClient constructor

* Analyzer

* Fix "the a" typos

* Rephrase global key API doc description

* more ui-as-code

* address review comments