Fixes flutter/flutter#68377

Should be a nullable string. Looks like --null-assertions does not cover the native binding code.

* isCloneOf for Image

* Update docs, add missing impl

Allows for reference counting of images before disposal.

This will allow multiple callers to hold a reference to an image and dispose of their reference without disposing the underlying image until all handles have been disposed.

This will be used by the framework to help resolve some of the kludge I was trying to introduce in flutter/flutter#64582

dart-lang/sdk@016e8880f0a Version 2.10.0-90.0.dev
dart-lang/sdk@34f636ce1d8 Revert "[vm/io] Fix FileSystemWatcher enum name typo."
dart-lang/sdk@7a02118a410 [vm/fuchsia]: Safely shutdown the async message loop.
dart-lang/sdk@334d3681467 [analyzer_plugin] Remove unused dart:async imports
dart-lang/sdk@047c0f860a5 [Analyzer] Support analyzing open files without open workspaces
dart-lang/sdk@f846d0e7ea0 [analyzer_cli] Remove unused dart:async imports
dart-lang/sdk@ba372d6e8a4 [dartdev] Remove unused dart:async import
dart-lang/sdk@30cfb228c00 [nnbd_migration] Remove unused dart:async imports
dart-lang/sdk@1134a0f17c8 [analysis_server] Remove unused dart:async imports
dart-lang/sdk@3317d47c7de [_fe_analyzer_shared] Remove unused dart:async import
dart-lang/sdk@0a036db5962 [vm/io] Fix FileSystemWatcher enum name typo.
dart-lang/sdk@000f3135a5c [analyzer] Remove unused dart:async imports
dart-lang/sdk@7817aa17967 [dartfix] Remove unused dart:async imports
dart-lang/sdk@0144087619f Version 2.10.0-89.0.dev
dart-lang/sdk@42dfb9d3046 Add `generateCallGraphWithDominators` method to generate a `CallGraph` from a precompiler trace.
dart-lang/sdk@01024dfa5a8 Issue 43200. Report ASSIGNMENT_TO_FINAL when 'final late' has an initializer.
dart-lang/sdk@ab16d79af97 Revert "Flow analysis changes to fix mixed-mode unsoundness loophole."
dart-lang/sdk@7363adca67a [infra] Update checked-in SDKs to 2.10.0-79.0.dev
dart-lang/sdk@d833f2f65c1 Flow analysis changes to fix mixed-mode unsoundness loophole.
dart-lang/sdk@33e4a6bc2a8 Revert "[vm] Have Read/WriteStream use (S)LEB128 for variable-length encoding."
dart-lang/sdk@d9dc24b53e7 Version 2.10.0-88.0.dev
dart-lang/sdk@7130dd4d3d9 [cfe] Report error on non-void setter return type
dart-lang/sdk@a7cb764aa45 [tests/ffi] Reinstate deleted test
dart-lang/sdk@39689eb07cd [co19] Roll co19 to 9c07e26d67665de7972ba6f7e87369933a978545
dart-lang/sdk@1f92293fd58 Revert "[dart:html] Add 'creates' type description to JS calls"
dart-lang/sdk@e44cf969c64 Fix creates value for getStats
dart-lang/sdk@15201ebe5f1 Version 2.10.0-87.0.dev
dart-lang/sdk@eb8dfee1074 [CFE] Clean up duplicate entries in spell checker lists

Co-authored-by: NDavid Iglesias <ditman@gmail.com>

* Manual merge or Dart into flutter a3815b6590...24c7666def

dart-lang/sdk@24c7666def Update tests that have the current version number hardcoded
dart-lang/sdk@f88ce7aef5 Increase Dart version to 2.10

* Update language version.

* Update license.

* Hpdate language version.

* Update license.

Refactors instantiateImageCodec and decodeImageFromPixels to provide intermediate data about the image width, height, and bytes per pixel. This allows for more fine grained control from Dart, particularly when trying to reason about how or whether to maintain aspect ratio in the targetWidth/targetHeight parameters.

This leaves the existing methods functional by re-implementing them to use the new ImmutableBuffer/ImageDescriptor class.

The ImmutableBuffer class is provided so that callers can avoid copying the image data multiple times if they wish to re-recreate the image descriptor.

Related Issues

This reverts commit f9acd080.

* use Object for operator==

* apply style guide for operator==

Adds an `allowUpscale` parameter to the Dart interfaces for instantiateImageCodec and decodeImageFromPIxels. If set to false, the image bounds will be clamped at their intrinsic dimensions.

A later commit will change the default to true.

Correctly describe the way aspect ratio is managed when one parameter is not specified.

* apply null safety syntax to mobile dart:ui

* nullability clean-ups

* null-annotate remaining engine code

* add nullability annotations to lib/ui/painting.dart

* Implement GetAllocationSize for Vertices

* Reflect vertex buffer size in pictures

We believe this may be implicated in a Windows-specific crash during the
Flutter Gallery integration test.

See:
https://github.com/flutter/flutter/issues/51896

This reverts commit f9b78c5d.

Image
Codec
FrameInfo
Scene/Picture toImage

* opt out dart:ui from nnbd

* Annotate tests as well

This reverts commit 4941ff7b.

This API is being removed from the Dart SDK.

web_ui support coming in https://github.com/flutter/flutter/issues/47163

This reverts commit 9f2daad6.

Constructing colors using `fromRGBO` should return the same values as the CSS
`rgba()` notation.  rgba(0, 0, 255, 0.5) is the same as `#0000ff80`

However `fromRGBO` sometimes creates a color with an off-by-one alpha value:

    expect(Color.fromRGBO(0, 0, 255, 0.5), Color(0x800000ff));

Expected: Color:<Color(0x800000ff)>
  Actual: Color:<Color(0x7f0000ff)>

If we use `withOpacity` to create the same color, it returns the correct color:

    expect(Color.fromRGBO(0, 0, 255, 1).withOpacity(0.5), Color(0x800000ff));

This should also be changed in lib/web_ui/lib/src/ui/painting.dart in a
followup change.

* Remove unused field
* Similarly remove _TypeNone from web_ui