This measures the wall clock time between a new frame being scheduled in dart code to the Vsync callback in the engine
It's an important source of lag which isn't shown in the top-level UI / Build time graphs, and can correlate with "invisible" missed/non-scheduled frames
I had to change a few unrelated timings in the test, it was only passing based on luck of sort order, and broke when I added more entries to the timeline.
Part of #129150
* Use `curly_braces_in_flow_control_structures` for `packages/flutter_driver`
* Use `curly_braces_in_flow_control_structures` for `packages/flutter_goldens`
* Use `curly_braces_in_flow_control_structures` for `packages/flutter_goldens_client`
* Use `curly_braces_in_flow_control_structures` for `packages/flutter_localizations`
* Use `curly_braces_in_flow_control_structures` for `packages/flutter_test`
* Use `curly_braces_in_flow_control_structures` for `packages/flutter_web_plugins`
* fix comments
* Use `curly_braces_in_flow_control_structures` for `packages/integration_test`
* fix indentation
Ensures all of the libraries that the application side code import are migrated to null safety. full null safety migration is blocked by json rpc 2 and a breaking change to vm service client.
As of flutter.dev/go/engine-cpu-profiling, we collect the CPU and
Memory usage. With work being done to collect GPU usage on iOS as well.
This adds them to the timeline summary.
Fixes: https://github.com/flutter/flutter/issues/58803
* 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
* Fix TODO syntax.
* Clarify messages for some timeouts, to aid debugging.
* Increase some other timeouts that were a needlessly short, to reduce sources of flakes.
* Remove some more timeouts that were mostly redundant, to remove complexity.
* Minor style cleanup.
* Remove some dangerous traps (specifically, hide the explicit start/end times in TimedEvent since they shouldn't matter).
