This reverts commit 8c44abc0.

* apply upcoming lint cast_nullable_to_non_nullable

* make RenderObjectElement.renderObject non-nullable

This reverts commit 0ab5ecc8.

https://github.com/flutter/flutter/issues/61496

* Revert "Revert "Add clipBehavior to widgets with clipRect (#55977)" (#58344)"

This reverts commit 1d395c5e.

* Add missed Overflow

* add language version 2.8 in packages/flutter

* enable non-nullable analyzer flag

This reverts commit cd593dae.

* Add clipBehavior to RenderFlex

* Add clipBehavior to FittedBox

* Add clipBehavior to Flex and FittedBox

* Add clipBehavior to UnconstrainedBox

* Add clipBehavior to Stack and Wrap

* Add clipBehavior to TextEditable

* Add clipBehavior to ListWheelScrollView

* Add clipBehavior to SingleChildScrollView

* Add clipBehavior to RenderViewportBase's widgets

Those widgets are NestedScrollView and ShrinkWrappingViewport.

* Fix tests

* Remove enum Overflow and fix typo

* Remove clipToSize

* Analyze fix

* Remove Mixin and other small fixes

* Fix tests and respect Stack's default clipBehavior

* Add Overflow back to make it non-breaking

* Restore clipBehavior to make it non-breaking

* Small fixes

* Fix rebase

This reverts commit 2132a0c7.

This reverts commit 69080e07.

* implicit-casts:false in flutter/lib/src/rendering

* address review comments

* Update project.pbxproj files to say Flutter rather than Chromium

Also, the templates now have an empty organization so that we don't cause people to give their apps a Flutter copyright.

* Update the copyright notice checker to require a standard notice on all files

* Update copyrights on Dart files. (This was a mechanical commit.)

* Fix weird license headers on Dart files that deviate from our conventions; relicense Shrine.

Some were already marked "The Flutter Authors", not clear why. Their
dates have been normalized. Some were missing the blank line after the
license. Some were randomly different in trivial ways for no apparent
reason (e.g. missing the trailing period).

* Clean up the copyrights in non-Dart files. (Manual edits.)

Also, make sure templates don't have copyrights.

* Fix some more ORGANIZATIONNAMEs

* 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

Bug #1: These didn't work with directional alignments, due to an error
in the types of the constructor arguments.

Bug #2: Pretty sure RenderSizedOverflowBox never worked at all. As
soon as I wrote a test for it, the test showed that there was a
fundamental bug in its performLayout method: it didn't set
parentUsesSize, but it immediately tried to use the child's size.

* enable lint unnecessary_new

* fix tests

* fix tests

* fix tests

* Fixes resulting from audit of issues links

I looked at every link to GitHub in our repo. For cases where we had a TODO that was waiting for a bug to be fixed, and the bug has now been fixed, I applied the pending change. For cases where the link was out of date, I updated the link.

* Update run_test.dart

skip this test again since it failed on linux and macos bots

This addresses #16593 by removing the unneeded assert in the setter for constrainedAxis. Null was meant to be allowed there.

This replaces #16599 and fixes #16593, reported by @maksimr

This updates the visual look of the Chip class, so that it scales properly in the face of text scale (and label widget size) changes, and bases its height off of the label widget's height, constraining the other widgets it contains to be the same height.

To do this properly, I had to implement a custom render object that will measure the height of the label, so the guts of this class are basically rewritten.

In addition, to allow the circle avatar to increase in size when the chip does, I added minRadius and maxRadius arguments to it, and I updated its color handling to use the light/dark primary colors of the theme in a smart way instead of just using black and white.

Updated and added tests.