Cut now explicitly updates the clipboard status.

This reverts commit 5fd259be.

Use the hasStrings clipboard method when possible instead of reading the contents of the clipboard.

This reverts commit 35ad43f2.

This reverts commit c26ed03c.

* Migrate to ChannelBuffers.push

* Move TestDefaultBinaryMessenger to its own file

* Apply deprecations and fix usages

This reverts commit a46139a2.

A very minimal right-click menu for Mac desktop.

selectionEnabled was not taken into account in:

key movement handling in RenderEditable
mouse drag handling in TextSelectionGestureDetectorBuilder

Fixes a bug where selection handles sometimes showed on web.

* add language version 2.8 in packages/flutter

* enable non-nullable analyzer flag

[a11y] Make sure RenderFractionalTranslation updates its semantics after the translation field is set (#48985)

* 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 missing trailing commas

* add more missing trailing commas

* add more and more missing trailing commas

Guard removePointer with addTearDown to avoid cascading test crash.