This reverts commit 3e25e60f.

Reland of #50707

af426986b Roll fuchsia/sdk/core/linux-amd64 from _k1WT... to Fjow3... (flutter/engine#17127) (#52539)

d7a00b8b0 Roll src/third_party/dart 7c2f62406bef..eb9c26bd378f (15 commits) (flutter/engine#17124) (#52523)

85e6b01ae Roll src/third_party/dart 33349076ee7f..7c2f62406bef (23 commits) (flutter/engine#17120) (#52519)

* Change onSort and add tests

* Add doc

* Regression test

* Remove if (true)

* Make test clearer

* Clearer comment

* TapGestureRecognizer no longer adds the pointer after it resets.

* Adds an assertion to make sure TapGestureRecognizer.startTrackingPointer is never called when _down is null

This reverts commit 1bf9d6f4.

This adds generation of some C++ keycode maps for various platforms.

This isn't meant for general use: it's so that the Flutter authors can keep the keycodes up to date with the Chromium and Android (and other) sources. It doesn't run continuously, it's only run occasionally (manually) to update the maps, because they don't change very often, and there is often manual work needed to make it function.

In this PR, I added output of various .cc files that write into an engine repo situated next to the flutter repo on disk. This is a starting point for implementing platform-side handling of key events.

c28d23068 Roll fuchsia/sdk/core/linux-amd64 from Yk03L... to _k1WT... (flutter/engine#17112) (#52508)

1aaf16988 Roll src/third_party/skia f0140ee00f95..1743144ab839 (2 commits) (flutter/engine#17111) (#52494)

* Fix suppportedLocales list

* Refactor integration tests for gen_l10n tool to catch exceptions

Reland of #52149

Revert "[flutter_tools] Update background isolates when performing hot reload/restart (#52149)" (#52476)

This reverts commit edd03a1a.

Just some very minor doc changes: an adjustment of my comments in #51495, and a typo fix.

When performing a hot restart, collect isolates without an attached flutter view and send a kill signal. These must have been spawned by running main, so restarting without removing them leads to isolate duplication.

When performing a hot reload, ensure that we send a reloadSources command to every isolate and not just uiIsolates.