* 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
Update the Slider and RangeSlider to the latest Material spec. This introduces an updated track, updated thumbs, updated tick marks, and a new value indicator shape. The old paddle value indicator shape is also updated so that text scaling works consistently.
For G3 Roll:
* Revert "MaterialButton must honor its minWidth and height parameters (#22919)"
This reverts commit a02332335a.
* Revert "Update uses of ButtonTheme.bar: pass along the current Theme's colorScheme (#22827)"
This reverts commit 655bf6a290.
* Revert "ButtonTheme.of().colorScheme defers to Theme (#22880)"
This reverts commit a590940e45.
* Revert "Bring TextTheme into alignment with the current Material spec (#22330)"
This reverts commit 8bfb4b3ee5.
* Revert "Added ColorScheme, updated ThemeData, ButtonTheme, material buttons (#22013)"
This reverts commit eea3465ae7.
* Manual adjustments to fix reversion issues.
Introduce an overall material "color scheme" and to make it possible to redefine how a component's visual properties bind to the color scheme and to the existing material Theme.
