relation to #47771

The PR itself looks good. I'm more concerned if we can have a Dart change like https://dart-review.googlesource.com/c/sdk/+/127921 but none of our framework tests would fail to notify that such Dart change is in some way breaking the Flutter framework. I also didn't notice any significant change in https://flutter-dashboard.appspot.com/benchmarks.html . @goderbauer : do you know if there's any integration test that's supposed to catch such Dart changes?

https://dart-review.googlesource.com/c/sdk/+/127921, it has merged in out own engine.
I run command of "flutter drive" to test performance that report build failed. My PR merged into dart warehouse, not synchronized into engine?

@liyuqian yeah I stopped it yesterday. I was trying to figure out how to fix this so happy to see this PR :)

The build is green again @yuanhuihui, is this ok to land?

I'll land to unblock the roll. Will revert if needed.

This seems to break the build

2019-12-27T09:51:44.476526: stdout: [+9570 ms] 00:10 �[32m+0�[0m�[31m -1�[0m: scrolling performance test complex_layout_scroll_perf �[1m�[31m[E]�[0m�[0m
2019-12-27T09:51:44.477108: stdout: [        ]   Invalid argument(s): durations is empty!
2019-12-27T09:51:44.498305: stdout: [  +21 ms]   package:flutter_driver/src/driver/timeline_summary.dart 167:7   TimelineSummary._averageInMillis
stdout: [        ]   package:flutter_driver/src/driver/timeline_summary.dart 33:12   TimelineSummary.computeAverageFrameBuildTimeMillis
stdout: [        ]   package:flutter_driver/src/driver/timeline_summary.dart 89:42   TimelineSummary.summaryJson
stdout: [        ]   package:flutter_driver/src/driver/timeline_summary.dart 130:4

Will revert for now

This PR needs to include a new hash in bin/internal/engine.version to pull over the appropriately patched Engine version that includes the change to Dart. It looks like any "green" engine build after flutter/engine@5a730c6 would do that.

It looks like flutter/engine@5a730c6 rolled into Engine cleanly so using that specific hash should work to get a clean roll into Framework.

All remaining issues fixed with the following PRs:

#47896
#47899

All remaining issues fixed with the following PRs:

#47896
#47899

In my own engine, we have fix flutter_gallery. Because of using a 7-day old engine, this timeline_summary PR failed to merge before. So I plan to submit a fixing flutter_gallery PR after the timeline_summary PR have merged. It seems that you have discovered and solved this problem now.