Remove 'must not be null' comments from painting and rendering libraries. - #134993

…amework libraries (#134994)

## Description

This removes all of the comments that are of the form "so-and-so must not be null" or "so-and-so must be non-null" from the cases where those values are defines as non-nullable values.

This PR removes them from the library in the repo that don't have anything to do with the framework.

This was done by hand, since it really didn't lend itself to scripting, so it needs to be more than just spot-checked, I think. I was careful to leave any comment that referred to parameters that were nullable, but I may have missed some.

In addition to being no longer relevant after null safety has been made the default, these comments were largely fragile, in that it was easy for them to get out of date, and not be accurate anymore anyhow.

This did create a number of constructor comments which basically say "Creates a [Foo].", but I don't really know how to avoid that in a large scale change, since there's not much you can really say in a lot of cases.  I think we might consider some leniency for constructors to the "Comment must be meaningful" style guidance (which we de facto have already, since there are a bunch of these).

## Related PRs
- #134984
- #134991
- #134992
- #134993

## Tests
 - Documentation only change.

…g libraries. (flutter/flutter#134993)

…library (#134992)

## Description

This removes all of the comments that are of the form "so-and-so (must not be null|can ?not be null|must be non-null)" from the cases where those values are defines as non-nullable values.

This PR removes them from the widgets library.

This was done by hand, since it really didn't lend itself to scripting, so it needs to be more than just spot-checked, I think. I was careful to leave any comment that referred to parameters that were nullable, but I may have missed some.

In addition to being no longer relevant after null safety has been made the default, these comments were largely fragile, in that it was easy for them to get out of date, and not be accurate anymore anyhow.

This did create a number of constructor comments which basically say "Creates a [Foo].", but I don't really know how to avoid that in a large scale change, since there's not much you can really say in a lot of cases.  I think we might consider some leniency for constructors to the "Comment must be meaningful" style guidance (which we de facto have already, since there are a bunch of these).

## Related PRs
- #134984
- #134991
- #134993
- #134994

## Tests
 - Documentation only change.

…g libraries. (flutter/flutter#134993)

…g libraries. (flutter/flutter#134993)

…g libraries. (flutter/flutter#134993)

…g libraries. (flutter/flutter#134993)

…g libraries. (flutter/flutter#134993)

…g libraries. (flutter/flutter#134993)

…g libraries. (flutter/flutter#134993)

…g libraries. (flutter/flutter#134993)

…g libraries. (flutter/flutter#134993)

…g libraries. (flutter/flutter#134993)

…g libraries. (flutter/flutter#134993)

…g libraries. (flutter/flutter#134993)

…g libraries. (flutter/flutter#134993)

…g libraries. (flutter/flutter#134993)

…g libraries. (flutter/flutter#134993)

…g libraries. (flutter/flutter#134993)

…g libraries. (flutter/flutter#134993)

…g libraries. (flutter/flutter#134993)

…g libraries. (flutter/flutter#134993)

Manual roll Flutter from 8936504 to f92884c (48 revisions)

Manual roll requested by dit@google.com

flutter/flutter@8936504...f92884c

2023-09-21 jiahaog@users.noreply.github.com Rename `debugProfilePlatformChannels` to a constant that works in release mode (flutter/flutter#134922)
2023-09-20 82763757+NobodyForNothing@users.noreply.github.com Mark ReastaurationManager not disposed (flutter/flutter#134832)
2023-09-20 82763757+NobodyForNothing@users.noreply.github.com cover more tests with leak tracing (flutter/flutter#134834)
2023-09-20 82763757+NobodyForNothing@users.noreply.github.com Fix leak in hardware_keyboard_test.dart (flutter/flutter#134380)
2023-09-20 sokolovskyi.konstantin@gmail.com Fix memory leak in _SelectableTextState (flutter/flutter#135049)
2023-09-20 engine-flutter-autoroll@skia.org Roll Flutter Engine from 39c0f2ea1f53 to 89d864552acd (4 revisions) (flutter/flutter#135169)
2023-09-20 ditman@gmail.com [deps] Update package:web dependency. (flutter/flutter#135174)
2023-09-20 yjbanov@google.com finer grained logging of Chromium launch sequence (flutter/flutter#135078)
2023-09-20 34871572+gmackall@users.noreply.github.com Upgrade AGP version in tracing_tests (flutter/flutter#134671)
2023-09-20 82763757+NobodyForNothing@users.noreply.github.com Cover cupertino/form_section_test with leak tracing (flutter/flutter#135158)
2023-09-20 sokolovskyi.konstantin@gmail.com Cover more test/widgets tests with leak tracking #7 (flutter/flutter#134943)
2023-09-20 goderbauer@google.com Enable strict-inference (flutter/flutter#135043)
2023-09-20 sokolovskyi.konstantin@gmail.com Cover more test/widgets tests with leak tracking #10 (flutter/flutter#135143)
2023-09-20 82763757+NobodyForNothing@users.noreply.github.com cover more tests with leak tracing (flutter/flutter#134833)
2023-09-20 ychris@google.com codeisn extension safe iOS framework (flutter/flutter#134966)
2023-09-20 engine-flutter-autoroll@skia.org Roll Flutter Engine from 6f256257b79f to 55314d08d792 (2 revisions) (flutter/flutter#135151)
2023-09-20 gspencergoog@users.noreply.github.com Remove 'must be non-null' and 'must not be null' comments in widgets library (flutter/flutter#134992)
2023-09-20 engine-flutter-autoroll@skia.org Roll Flutter Engine from 5f82fc2f6f24 to 6f256257b79f (1 revision) (flutter/flutter#135147)
2023-09-20 43054281+camsim99@users.noreply.github.com [Android] Add Java/AGP/Gradle incompatibility warning to `flutter create` (flutter/flutter#131444)
2023-09-20 engine-flutter-autoroll@skia.org Roll Packages from d4e2454 to 51e74b9 (12 revisions) (flutter/flutter#135145)
2023-09-20 gspencergoog@users.noreply.github.com Remove 'must not be null' comments from various libraries. (flutter/flutter#134984)
2023-09-20 engine-flutter-autoroll@skia.org Roll Flutter Engine from 6535421b30d3 to 5f82fc2f6f24 (2 revisions) (flutter/flutter#135142)
2023-09-20 engine-flutter-autoroll@skia.org Roll Flutter Engine from 67d4aaef3c7b to 6535421b30d3 (1 revision) (flutter/flutter#135139)
2023-09-20 sokolovskyi.konstantin@gmail.com Cover more test/widgets tests with leak tracking #8 (flutter/flutter#135045)
2023-09-20 sokolovskyi.konstantin@gmail.com Cover more test/widgets tests with leak tracking #9 (flutter/flutter#135054)
2023-09-20 engine-flutter-autoroll@skia.org Roll Flutter Engine from 83b4df415bf3 to 67d4aaef3c7b (1 revision) (flutter/flutter#135128)
2023-09-20 engine-flutter-autoroll@skia.org Roll Flutter Engine from df4e6c079682 to 83b4df415bf3 (2 revisions) (flutter/flutter#135102)
2023-09-20 engine-flutter-autoroll@skia.org Roll Flutter Engine from 9c6b2500282b to df4e6c079682 (1 revision) (flutter/flutter#135101)
2023-09-20 engine-flutter-autoroll@skia.org Roll Flutter Engine from 24f7ac38dfa2 to 9c6b2500282b (3 revisions) (flutter/flutter#135098)
2023-09-20 engine-flutter-autoroll@skia.org Roll Flutter Engine from 36379b62bec8 to 24f7ac38dfa2 (2 revisions) (flutter/flutter#135096)
2023-09-20 engine-flutter-autoroll@skia.org Roll Flutter Engine from 81b93fc4a2cc to 36379b62bec8 (2 revisions) (flutter/flutter#135095)
2023-09-20 engine-flutter-autoroll@skia.org Roll Flutter Engine from 5a924a9017d7 to 81b93fc4a2cc (2 revisions) (flutter/flutter#135093)
2023-09-20 gspencergoog@users.noreply.github.com Remove 'must be non-null' and 'must not be null' comments from material. (flutter/flutter#134991)
2023-09-20 34871572+gmackall@users.noreply.github.com Unpin url launcher (remake) (flutter/flutter#134958)
2023-09-20 engine-flutter-autoroll@skia.org Roll Flutter Engine from a7af55c56aa6 to 5a924a9017d7 (10 revisions) (flutter/flutter#135085)
2023-09-20 engine-flutter-autoroll@skia.org Manual roll Flutter Engine from a7af55c56aa6 to 0d7db40c27fd (7 revisions) (flutter/flutter#135079)
2023-09-20 gspencergoog@users.noreply.github.com Remove 'must not be null' comments from painting and rendering libraries. (flutter/flutter#134993)
2023-09-20 82763757+NobodyForNothing@users.noreply.github.com cover more tests with leak tracking (flutter/flutter#134837)
2023-09-20 xilaizhang@google.com [flutter roll] Revert "Native assets support for Linux" (flutter/flutter#135069)
2023-09-20 engine-flutter-autoroll@skia.org Manual roll Flutter Engine from 10c480310926 to a7af55c56aa6 (4 revisions) (flutter/flutter#135071)
2023-09-19 zanderso@users.noreply.github.com Retry Linux web tests 1 time on roll presubmit (flutter/flutter#135073)
2023-09-19 ditman@gmail.com [web] Encode AssetManifest.bin as JSON and use that on the web. (flutter/flutter#131382)
2023-09-19 polinach@google.com Specify suggested format in doc comment. (flutter/flutter#134887)
2023-09-19 engine-flutter-autoroll@skia.org Manual roll Flutter Engine from 28f14e6eec4f to 10c480310926 (6 revisions) (flutter/flutter#135066)
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