* Add SizedBox.square() constructor

* Fix comment and move test case to the right file

* Add missing import statement

* Add link to documentation in error message

The current WebDriver message is incomplete. Add link to
the documentation on WebDrivers for different browsers
to help troubleshooting.

6e03bbd42 Roll Dart SDK from 4882a5e99192 to 93ff88f22f01 (2 revisions) (flutter/engine#26679) (#84342)

ad6c83164 Roll Dart SDK from b7c2babecc88 to 4882a5e99192 (1 revision) (flutter/engine#26675) (#84323)

This switches the sample analysis code to use package:flutter_lints instead of the flutter repo analysis options, so that they are compatible with a similar change to DartPad.