Flutter commands all default to --preview-dart-2. Eliminate support for
the use of this option and the previewDart2 parameter in dev/devicelab
tests.

Normalize file path to non-Windows so string path comparison works.

Clarify the intent of these tests.

https://github.com/flutter/engine/compare/252da4808277...dc7b5eb89da3

git log 252da4808277..dc7b5eb89da3 --no-merges --oneline
dc7b5eb89 Use Skia normalize again after Skia precision fix. (flutter/engine#6121)
1c7682418 entering a character with a selection deletes the selection (flutter/engine#6113)
9fc355d2c Roll src/third_party/skia cd7907b57d76..7ed0eae0cd13 (1 commits) (flutter/engine#6120)
6586016da Roll src/third_party/skia f7c723c93d26..cd7907b57d76 (1 commits) (flutter/engine#6119)
1fa5fe6a0 Roll src/third_party/skia eb0bb732f43f..f7c723c93d26 (3 commits) (flutter/engine#6118)


The AutoRoll server is located here: https://autoroll.skia.org/r/flutter-engine-flutter-autoroll

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+/master/autoroll/README.md

If the roll is causing failures, please contact the current sheriff, who should
be CC'd on the roll, and stop the roller if necessary.

* Pass uri instead of filepaths when hot-reloading.

Bug: https://github.com/flutter/flutter/issues/21168

* Remove imports. Enable another test

* Restore skipping of test on mac

This adds links to the already existing animated diagrams in the asset-for-api-docs repo.

* Split analysis steps out of dev/bots/test.dart into dev/bots/analyze.dart.

This allows to run analysis step with command line arguments that are only applicable to flutter analyze(like --dart-sdk, needed for dart-flutter-engine head-head-head bot).

* Add forgotten dev/bots/analyze.dart

* Refactor common code from analyze.dart and test.dart into run_command.dart

* Remove comments, add header

* [FAB] Updated tooltip touch target.

* Remove "new" keyword

* [FAB] Updated tooltip touch target.

* "long press button edge"

* remove new

* remove new

* put "new" keywords back in

* Remove check for childless tooltip

* Added regression test - tooltip works on edge of FAB which has no child.

Added helper method to find the right edge of a in the tests.

* Changed "find.byType(text)" to "find.text('Add')"

When switching between channels, we were leaving around the version freshness stamp file (bin/cache/flutter_version_check.stamp), which meant that the flutter tool would read from that file to see what the cached date of the most recent commit to the current channel (branch) was. The problem was that since the file was created while on the previous channel, the cached date was for the wrong channel, so if you switch from master to beta, flutter would think that the channel was out of date, and a new version was available, at least for three days after the first time it checked (after three days since the last time the freshness was checked, the cached date would get updated).

This PR modifies the channel command to remove that stamp file whenever the user switches channels, so that the cached date will be from the right channel when it is recreated.

Fixes #21134

https://github.com/flutter/engine/compare/a02a94e0182c...252da4808277

git log a02a94e0182c..252da4808277 --no-merges --oneline
252da4808 Roll src/third_party/skia 1b714becff8b..eb0bb732f43f (2 commits) (flutter/engine#6116)
cba35d33a Roll Tonic (flutter/engine#6114)
7a599658d Roll src/third_party/skia 1f0fb09d5e35..1b714becff8b (11 commits) (flutter/engine#6115)
4a6990734 Fix libtxt unit tests (flutter/engine#6111)
c765bee59 Fix tilt by using custom normalize impl to avoid strange skia normalize behavior (flutter/engine#6106)
9fde6e0d8 Roll src/third_party/skia a81c2be75adc..1f0fb09d5e35 (13 commits) (flutter/engine#6110)


The AutoRoll server is located here: https://autoroll.skia.org/r/flutter-engine-flutter-autoroll

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+/master/autoroll/README.md

If the roll is causing failures, please contact the current sheriff, who should
be CC'd on the roll, and stop the roller if necessary.

This is follow-up to https://github.com/flutter/flutter/pull/21143.

Workaround is not needed since real fix has landed in dart sdk: https://dart-review.googlesource.com/c/sdk/+/62729.

https://github.com/flutter/engine/compare/eceb722b7111...a02a94e0182c

git log eceb722b7111..a02a94e0182c --no-merges --oneline
a02a94e01 Roll src/third_party/skia 33f34556b5fc..a81c2be75adc (1 commits) (flutter/engine#6109)


The AutoRoll server is located here: https://autoroll.skia.org/r/flutter-engine-flutter-autoroll

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+/master/autoroll/README.md

If the roll is causing failures, please contact the current sheriff, who should
be CC'd on the roll, and stop the roller if necessary.

https://github.com/flutter/engine/compare/f3ff83a5db71...eceb722b7111

git log f3ff83a5db71..eceb722b7111 --no-merges --oneline
eceb722b7 Roll Dart to dart-lang/sdk@760a9690c2 (flutter/engine#6108)
be9d8ffbb Roll src/third_party/skia 5f0726b01019..33f34556b5fc (1 commits) (flutter/engine#6107)


The AutoRoll server is located here: https://autoroll.skia.org/r/flutter-engine-flutter-autoroll

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+/master/autoroll/README.md

If the roll is causing failures, please contact the current sheriff, who should
be CC'd on the roll, and stop the roller if necessary.

This is a bit of a stab in the dark for a flake sometimes seen on bots (but I can't repro locally) #20822. Detaching from a Flutter app currently seems to terminate it, so it may be the cause of the "app not found" when trying to stop the app subsequently.

This change means we stop the app from the main process first, before terminating the attach process.

Bug: https://github.com/flutter/flutter/issues/17833

* Roll engine to 56139397e6ae1257bdabd1ef79ff7aca96c67d4.6

Changes since last roll:
```
56139397e Roll src/third_party/skia 7ba1d64f0706..5f0726b01019 (12 commits) (#6104)
47a1ce0e6 Allow embedders to set the root surface transformation. (#6085)
```

* Roll engine to f3ff83a5db71262d240aa5337a2a9a22c73c4749. (dart roll).

* Add const

* Add ignore analyzer prefer_const_constructors_in_immutables

Update CONTRIBUTING.md to suggest Android Studio and fix Mac command to install android-platform-tools. (#19537)

https://github.com/flutter/engine/compare/af42b6dc95bd...56bad48ab2ed

git log af42b6dc95bd..56bad48ab2ed --no-merges --oneline
56bad48ab expose bold text flag in accessibility features for iOS (flutter/engine#6072)
ad4e87d07 Convert synthesized Android motion events to long and not to int. (flutter/engine#6103)
f05b08b7b Roll src/third_party/skia f125111ca733..7ba1d64f0706 (18 commits) (flutter/engine#6102)
eb9738610 Roll src/third_party/skia 0fdc53f9ffc6..f125111ca733 (10 commits) (flutter/engine#6100)
06b8fa4ed Roll src/third_party/skia dd04bec39cea..0fdc53f9ffc6 (13 commits) (flutter/engine#6098)
bf078042d Roll ICU to c56c671998902fcc4fc9ace88c83daa99f980793 (flutter/engine#6097)
c867305c3 Unconditionally set resource id to empty string (flutter/engine#6096)
b4b1d0578 Roll src/third_party/skia e00fe30b8fe7..dd04bec39cea (4 commits) (flutter/engine#6095)
8694036a6 Roll src/third_party/skia 420696961c8c..e00fe30b8fe7 (1 commits) (flutter/engine#6094)


The AutoRoll server is located here: https://autoroll.skia.org/r/flutter-engine-flutter-autoroll

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+/master/autoroll/README.md

If the roll is causing failures, please contact the current sheriff, who should
be CC'd on the roll, and stop the roller if necessary.

* Fix coverage collection crash

Based on Jason's patch in https://github.com/flutter/flutter/pull/19546/

This is more or less the same but I tried to avoid using `dynamic`.

* Improve argument and variable names in flutter_platform

* Don't bother with reduce, since the order is guaranteed.

* Remove workaround for dart-lang/dartdoc#1125

* Update update_icons.dart for optional const and to remove markup stripping workaround

Apparently Gradle leaks memory and it's causing failures.

* Don't time out if process terminates when told to stop but response was not processed

While trying to reproduce #20822 I found a condition where the app may quit before the `app.stop` response is received but this code (which is called in integration test teardown) would sit around waiting and time out. With this change, the process exit is considered a valid response to the stop request.

* Add process exit to log for better errors in failures

This log can be turned on for debugging but is also dumped when a test fails (in certain conditions). With this in the log, it'll be clear if the timeout is because we're waiting for an event but the process quit.