* 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 structured errors in Animations, TabView, ChangeNotifier

* Add structured error on MaterialPageRoute, BoxBorder, DecorationImagePainter, TextSpan

* Add structured errors in Debug

* Fix test errors

* Add structured errors in Scaffold and Stepper

* Add structured errors in part of Rendering Layer

* Fix failing test due to FloatingPoint precision

* Fix failing tests due to precision error and not using final

* Fix failing test due to floating precision error with RegEx instead

* Add structured error in CustomLayout and increase test coverage

* Add structured error & its test in ListBody

* Add structured error in ProxyBox and increase test coverage

* Add structured error message in Viewport

* Fix styles and add more assertions on ErrorHint and DiagnosticProperty

* Add structured error in scheduler/binding and scheduler/ticker
Signed-off-by: Albertus Angga Raharja <albertusangga@google.com>

* Add structured error in AssetBundle and TextInput
Signed-off-by: Albertus Angga Raharja <albertusangga@google.com>

* Add structured errors in several widgets #1
Signed-off-by: Albertus Angga Raharja <albertusangga@google.com>

* Remove unused import
Signed-off-by: Albertus Angga Raharja <albertusangga@google.com>

* Add assertions on hint messages
Signed-off-by: Albertus Angga Raharja <albertusangga@google.com>

* Fix catch spacing
Signed-off-by: Albertus Angga Raharja <albertusangga@google.com>

* Add structured error in several widgets part 2 and increase code coverage
Signed-off-by: Albertus Angga Raharja <albertusangga@google.com>

* Add structured error in flutter_test/widget_tester

* Fix floating precision accuracy by using RegExp
Signed-off-by: Albertus Angga Raharja <albertusangga@google.com>

* Remove todo to add tests in Scaffold showBottomSheet
Signed-off-by: Albertus Angga Raharja <albertusangga@google.com>

* Fix reviews by indenting lines and fixing the assertion orders
Signed-off-by: Albertus Angga Raharja <albertusangga@google.com>

* Fix failing tests due to renaming class
Signed-off-by: Albertus Angga Raharja <albertusangga@google.com>

* Try skipping the NetworkBundleTest
Signed-off-by: Albertus Angga Raharja <albertusangga@google.com>

* Remove leading space in material/debug error hint
Signed-off-by: Albertus Angga Raharja <albertusangga@google.com>

Breaking change to extremely rarely used ParentDataWidget.debugDescribeInvalidAncestorChain api changing the return type of the method from String to DiagnosticsNode.

- Fixed the bug where CupertinoRefreshControl doesn't work in the gallery demo on Android.
- Updated documentation on CupertinoRefreshControl
- Added comments to the gallery demo
- Added concrete examples to ScrollPhysics

* 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

If the scroll is out of range for any reason (for instance, changing scroll physics or manually messing with scroll position), the spring simulation causes the scroll position to slingshot towards the end. Also, before this change, `end` was unused.

* enable lint unnecessary_new

* fix tests

* fix tests

* fix tests

* lint unnecessary_new on samples

* fix tests

Fixes #19523

* Fine-tune iOS's scroll start feel

* remove negations in doc

* Our own dart-side gesture arena also contributes to the 'jerk'. Make sure that snap is accounted as well.

* Added more code comments from review.

* Small glow overscroll dartdoc addition

* Directly specify [MaterialApp]

* review

* Add a minimum distance that needs breaking on iOS each time scrolls stopped.

* Testing and tests

* tweak docs

* review

I got tired of drive-by spelling fixes, so I figured I'd just take care of them all at once.

This only corrects errors in the dartdocs, not regular comments, and I skipped any sample code in the dartdocs. It doesn't touch any identifiers in the dartdocs either. No code changes, just comments.

* Record original pointer event timestamp

* review

* review

* review

* Matched motions with iOS. Didn’t add overscroll spring clamps and fix tests yet.

* clamp max overscroll transfer

* Add test

* review notes, moved things around

* remove function passing indirection

* review

* Replace stopwatch with timestamp from #11988

* move static

* Review

`stiffness` is the name of a spring's `k` input on [iOS](https://developer.apple.com/documentation/quartzcore/caspringanimation), [Android](https://developer.android.com/topic/libraries/support-library/preview/spring-animation.html), and the [Web](https://github.com/skevy/wobble/blob/bbc0f831e234f2d24fb905f2ec278c134d69ed68/src/index.js#L11-L22).  To ensure the API is familiar to and easily understood by developers coming from other platforms, Flutter should follow this convention as well.

This is a minimally-breaking change.  Across [all of GitHub](https://github.com/search?l=Dart&q=springConstant&type=Code&utf8=%E2%9C%93), there are only 2 uses of the `springConstant` API (in Mondrian).  Those can be easily changed to use this name.

Closes #11684

* Make the drag resistance non-linear

* Let the easing of overscroll have a spring effect too

* Add tests and prevent possible drift by having a slightly smaller resistance when easing the overscroll

* lint

* Adjust the defaults behaviour of scroll views.

Now, primary scroll views scroll by default. Others only scroll if necessary.

* apply suggested changes

This patch reworks some of the guts of scrolling to make it easier to
implement nested scrolling effects. The actually nested scrolling effect
will be included in a later patch.

Covers lib/ in package:flutter.

This feature lets you see a portion of the next and previous page in a
PageView.

Fixes #8408

Previously, a ListView would always accept user input, even if it wasn't
actually scrollable. Now, by default, we don't accept user input if there's no
scroll range. You can override this behavior using the ScrollPhysics.

Fixes #8276
Fixes #8278
Fixes #8271