The `ForwardingGestureRecognizers` to have back reference to the `PlatformViewsController` so it can access `FlutterViewController` when its available  (#20708)

FlutterViewControllers.

controllers instead of views.

Remove the dummy rasterizer delegate now that flutter_runner is in tree, and cleanup ctor params (#20486)

This reverts commit 8d08e6c3.

* fix ios layout change cause the accessibility focus to jump randomly.

* format

* addressing review comments

* Implement Clipboard hasStrings method on iOS

* Test call to hasStrings

* Formatting fixes

* Move test to its own file

* Alphabetical order

* Update licenses

* arguments nil instead of empty dictionary

* Guarantee hasStrings will be true when tested

* Formatting

P0 bug fix

* Manual roll of Dart from 24c7666def...40fd1c456e

dart-lang/sdk@40fd1c456e Revert "[dart:io] Add Abort() on HttpClientRequest"
dart-lang/sdk@17d7296a42 [vm/nnbd/bytecode] Fix reuse of type arguments in bytecode
dart-lang/sdk@58b6f40c73 Issue 42797. Understand in legacy libraries that a function returning Never (in Null Safety library) never returns. (reland)
dart-lang/sdk@fc8a6d9f9b [VM/compiler] Dereference TypeRef literal when propagating constants.
dart-lang/sdk@0689ec527a Move "test.dart" (well, most of its contents) into pkg/test_runner.
dart-lang/sdk@1094b3c61d Prepare static error test updater tool to handle web tests.
dart-lang/sdk@b258585f2f [observatory] Migrate from deprecated isInstanceOf to isA.
dart-lang/sdk@dfe1d9b682 Disable OverrideContributor for Cider.
dart-lang/sdk@aea99b2f5c scope debug property assist to Diagnosticables
dart-lang/sdk@4b96f20a79 [dart:io] Add Abort() on HttpClientRequest
dart-lang/sdk@1b1a39708c [build] Use frameworks instead of libs
dart-lang/sdk@3fef522496 Revert "Reland "[vm] Replaces fuchsia.deprecatedtimezone""
dart-lang/sdk@8c664d4f3f Revert "Issue 42797. Understand in legacy libraries that a function returning Never (in Null Safety library) never returns."
dart-lang/sdk@2efb5bebc7 [ dart:_http ] Fix typo in HTTP response timeline event
dart-lang/sdk@0884dae36c Revert "Fix the #include path for ICU headers"
dart-lang/sdk@5171534e81 Scope tweaks. Report REFERENCED_BEFORE_DECLARATION in more places.
dart-lang/sdk@6bba75079a Issue 42797. Understand in legacy libraries that a function returning Never (in Null Safety library) never returns.
dart-lang/sdk@b4ebbb7f5c [build] Update gn to match Fuchsia
dart-lang/sdk@cb428a7a02 [dart2js] Remove old bug work around in collector.
dart-lang/sdk@08663c20ab Change flutter patch to match existing DEPS on master branch
dart-lang/sdk@146ad014d9 update js/meta for the 2.10 dev sdk
dart-lang/sdk@488c718793 [co19] Roll co19 to d79951e06e443213243e54c2c32694b79a221b65
dart-lang/sdk@ba20edd7be Add patch for flutter-engine when changing to version 2.10

* Rev buildroot to latest version.

* Update license.

* update.

* Update gn revision.

* Format BUILD.gn files as the gn revision has been updated.

This is part of a larger effort to expose the difference between GrDirectContext,
which runs on the GPU thread and can directly perform operations like uploading
textures, and GrRecordingContext, which can only queue up work to be delivered
to the GrDirectContext later.

iOS now matches Android behavior in that empty selections put the cursor at the start of the field.

* remove obsolete check

* FML_DCHECK flutter_view_ in methods that actually use it

* Makes IOS dispatchs showOnCcreen action for header semantics nodes

* update

* format

Tweak the primary flutter build rule so that fuchsia is more similar to
other platforms in how tests and the shell are built.

Only embedder_unittests and GLFW tests are disabled on Fuchsia now.

TEST: Ran unittests on host/fuchsia; workstation on fuchsia
BUG: fxb/53847, fxb/54056

Changed iOS channels to start cleaning up the accessibility handler when the bridge is deleted (#19556)

Started cleaning up the accessibility handler when the bridge is
deleted and made nilling out channels safer by making sure they don't
overwrite newly setup handlers.

UIKit does not guarantee that the application is in the active state when it
lays out it subviews. However, in `viewDidLayoutSubviews`, Flutter attempts to
create the render surface and wait for the first frame. These operations require
GPU access which is forbidden when in the background on iOS. This layout while
in the background only seems to happen under very specific circumstances as
described in the reproducible test case. Notably, this behavior cannot be
reproduced when the application is just launched with the "Background Fetch"
XCode run scheme. The other instance of invocations to create the rendering
surface have been audited and I can confirm that those are already in the
correct lifecycle callbacks. This was the only instance where the surface
creation was in a non-lifecycle callback.

Fixes https://github.com/flutter/flutter/issues/55969
(This issue has a clear reproducible test case and was used as the basis for
verification.)
Fixes https://github.com/flutter/flutter/issues/57676
(This is significantly harder to reproduce but the issue looks to be the same. I
tried this patch on multiple devices overnight and could not reproduce this.)

This underlying cause here was identified by the enhanced GPU error reporting
introduced in iOS 14. I am not able to submit those patches because the Beta
builders are not available on infra. I will submit those when available so that
issues like this have more actionable error messages in the future.