Without this, developers have to override `onReportTimings` to listen for `FrameTiming`.
That can potentially break previous `onReportTimings` listeners if they forget to call
the old listener in their new callback.
This PR replaces the similar RP in the framework: https://github.com/flutter/flutter/pull/38574
Once this PR landed, we'll have to create another framework PR to use the stream to replace
`onReportTimings` usages.
Once that's done, we can then propose the breaking change of removing the deprecated
`onReportTimings`.
Using it, a Flutter app can monitor missing frames in the release mode, and a custom Flutter runner (e.g., Fuchsia) can add a custom FrameRasterizedCallback.
Related issues:
https://github.com/flutter/flutter/issues/26154https://github.com/flutter/flutter/issues/31444https://github.com/flutter/flutter/issues/32447
Need review as soon as possible so we can merge this before the end of May to catch the milestone.
Tests added:
* NoNeedToReportTimingsByDefault
* NeedsReportTimingsIsSetWithCallback
* ReportTimingsIsCalled
* FrameRasterizedCallbackIsCalled
* FrameTimingSetsAndGetsProperly
* onReportTimings preserves callback zone
* FrameTiming.toString has the correct format
This will need a manual engine roll as the TestWindow defined in the framework needs to implement onReportTimings.
* preserve Window callback zones
Run Window callbacks in the zone they are registered in. This is consistent with how other native API work, such as `scheduleMicrotask`, `Timer`, and `dart:io`. This also enables the developers to use the `Zone` API to capture and log unhandled Dart errors.
* refactor wrapping
* new line
* fewer if checks; group getters/setters/fields
* inline _invokeOnPointerDataPacket
