* add missing trailing commas

* add more missing trailing commas

* add more and more missing trailing commas

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.

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

* Splitting golden file versioning out as an argument of matchesGoldenFile

* Fixing description implementation.

* Removing unused imports

* Removing unused import

* Review feedback

This reverts commit d92b3b40.

Revert "Merge branch 'master' into master"

This reverts commit e3a03c04, reversing
changes made to 64749826.

* Re-enable const

Fixes https://github.com/flutter/flutter/issues/31517

Commented out skips in golden framework tests and transitioned from matchesGoldenFile to matchesSkiaGoldFile.

* 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

See https://github.com/flutter/flutter/issues/23890

* enable lint unnecessary_new

* fix tests

* fix tests

* fix tests

* Visibility widget

This attempts to address the confusion around how to hide a widget subtree.

* Apply review comments

* More clarifications