* Added properties in DropdownFormField to match DropdownButton

* Minor style guide related changes

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.

Fixed an issue with a DropdownButton crashing when a style was used that didn't include a fontSize.

Revert "Merge branch 'master' into master"

This reverts commit e3a03c04, reversing
changes made to 64749826.

* 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

* Adds DropDownFormField Convenience Class

* Future<void> main

* Future<void>.delayed

* prefer_void_to_Null

* address review comments

If `items` or `onChanged` is null the button will be disabled, the down arrow will be grayed out, and
the new `disabledHint` will be shown (if provided).

* Adds comments clarifying the procedure used to render the menu as well as tests verifying various dropdown menu button positioning and initial scroll states.

In long lists this resulted in the dropdown scrolling to the very last
item in its list. Now clamping the value at `0.0`. Added a test to
verify that the selected item aligns with the button to test the offset.

Fixes flutter/flutter#15346

* enable lint unnecessary_new

* fix tests

* fix tests

* fix tests

* Fix Dropdown where icon not set to end of button

* Expand DropdownButton based on isExpanded flag

* Add dropdown golden tests

Fixes #13135, #16606

It was causing problems rolling Flutter into Fuchsia

* re-enable lint unnecessary_const

* remove trailling whitespaces

* remove unnecessary const (after merge)

This reverts commit cc1cf13e.

This is not a grand refactor yet, it's just cleaning up what we have
already, so that people who keep using this API (e.g. dialogs) have
something coherent to deal with.

The major changes are that Navigator and NavigatorState have the same
API now, that most of the examples use `<void>` instead of `<Null>`,
that the navigator observer can see replaces, and that the `settings`
is moved from ModalRoute to Route. I also cleaned up some of the API
documentation.

* spelling: accommodate

* spelling: allotted

* spelling: anonymous

* spelling: artificial

* spelling: associated

* spelling: asset

* spelling: button

* spelling: canvas

* spelling: compatibility

* spelling: coverage

* spelling: condition

* spelling: decoration

* spelling: deferring

* spelling: diameter

* spelling: direction

* spelling: displacement

* spelling: dropdown

* spelling: needing

* spelling: environment

* spelling: exited

* spelling: expansion

* spelling: explore

* spelling: families

* spelling: horizontal

* spelling: increment

* spelling: indices

* spelling: internationalization

* spelling: labrador

* spelling: localizations

* spelling: midflight

* spelling: milliseconds

* spelling: minimum

* spelling: multiple

* spelling: multiplication

* spelling: navigator

* spelling: overridden

* spelling: package

* spelling: performance

* spelling: platform

* spelling: porsche

* spelling: position

* spelling: preceded

* spelling: precede

* spelling: precedence

* spelling: print

* spelling: property

* spelling: readily

* spelling: reproducibility

* spelling: rounded

* spelling: scroll

* spelling: separate

* spelling: separator

* spelling: services

* spelling: specific

* spelling: specify

* spelling: synchronously

* spelling: through

* spelling: timeout

* spelling: triangle

* spelling: trivial

* spelling: unusual

* spelling: then

* spelling: vertically

* spelling: visible

* spelling: visited

* spelling: voice