Web macrobenchmark: bench_mouse_region_grid_hover now tests hitTestDuration (#60554)

dev/benchmarks/macrobenchmarks/lib/src/web/bench_mouse_region_grid_hover.dart

@@ -36,11 +36,17 @@ class _NestedMouseRegion extends StatelessWidget {
 ///
 /// Measures our ability to hit test mouse regions.
 class BenchMouseRegionGridHover extends WidgetRecorder {
-  BenchMouseRegionGridHover() : super(name: benchmarkName);
+  BenchMouseRegionGridHover() : super(name: benchmarkName) {
+    tester = _Tester(onDataPoint: handleDataPoint);
+  }
 
   static const String benchmarkName = 'bench_mouse_region_grid_hover';
 
-  final _Tester tester = _Tester();
+  _Tester tester;
+
+  void handleDataPoint(Duration duration) {
+    profile.addDataPoint('hitTestDuration', duration, reported: true);
+  }
 
   // Use a non-trivial border to force Web to switch painter
   Border _getBorder(int columnIndex, int rowIndex) {
@@ -62,6 +68,7 @@ class BenchMouseRegionGridHover extends WidgetRecorder {
       started = true;
       SchedulerBinding.instance.addPostFrameCallback((Duration timeStamp) async {
         tester.start();
+        registerDidStop(tester.stop);
       });
     }
     super.frameDidDraw();
@@ -127,6 +134,10 @@ class _UntilNextFrame {
 }
 
 class _Tester {
+  _Tester({this.onDataPoint});
+
+  final ValueSetter<Duration> onDataPoint;
+
   static const Duration hoverDuration = Duration(milliseconds: 20);
 
   bool _stopped = false;
@@ -150,7 +161,11 @@ class _Tester {
 
   Future<void> _hoverTo(Offset location, Duration duration) async {
     currentTime += duration;
+    final Stopwatch stopwatch = Stopwatch()..start();
     await gesture.moveTo(location, timeStamp: currentTime);
+    stopwatch.stop();
+    if (onDataPoint != null)
+      onDataPoint(stopwatch.elapsed);
     await _UntilNextFrame.wait();
   }
 

dev/benchmarks/macrobenchmarks/lib/src/web/bench_mouse_region_grid_scroll.dart

@@ -43,12 +43,7 @@ class BenchMouseRegionGridScroll extends WidgetRecorder {
       started = true;
       SchedulerBinding.instance.addPostFrameCallback((Duration timeStamp) async {
         tester.start();
-        final VoidCallback localDidStop = didStop;
-        didStop = () {
-          if (localDidStop != null)
-            localDidStop();
-          tester.stop();
-        };
+        registerDidStop(tester.stop);
       });
     }
     super.frameDidDraw();

dev/benchmarks/macrobenchmarks/lib/src/web/recorder.dart

@@ -345,8 +345,11 @@ abstract class WidgetRecorder extends Recorder implements FrameRecorder {
   /// pumping frames automatically.
   Widget createWidget();
 
+  final List<VoidCallback> _didStopCallbacks = <VoidCallback>[];
   @override
-  VoidCallback didStop;
+  void registerDidStop(VoidCallback fn) {
+    _didStopCallbacks.add(fn);
+  }
 
   @override
   Profile profile;
@@ -373,7 +376,8 @@ abstract class WidgetRecorder extends Recorder implements FrameRecorder {
     if (shouldContinue()) {
       window.scheduleFrame();
     } else {
-      didStop();
+      for (final VoidCallback fn in _didStopCallbacks)
+        fn();
       _runCompleter.complete();
     }
   }
@@ -437,8 +441,11 @@ abstract class WidgetBuildRecorder extends Recorder implements FrameRecorder {
   /// consider using [WidgetRecorder].
   Widget createWidget();
 
+  final List<VoidCallback> _didStopCallbacks = <VoidCallback>[];
   @override
-  VoidCallback didStop;
+  void registerDidStop(VoidCallback fn) {
+    _didStopCallbacks.add(fn);
+  }
 
   @override
   Profile profile;
@@ -484,7 +491,8 @@ abstract class WidgetBuildRecorder extends Recorder implements FrameRecorder {
       showWidget = !showWidget;
       _hostState._setStateTrampoline();
     } else {
-      didStop();
+      for (final VoidCallback fn in _didStopCallbacks)
+        fn();
       _runCompleter.complete();
     }
   }
@@ -942,9 +950,8 @@ String _ratioToPercent(double value) {
 /// Implemented by recorders that use [_RecordingWidgetsBinding] to receive
 /// frame life-cycle calls.
 abstract class FrameRecorder {
-  /// Called by the recorder when it stops recording and doesn't need to collect
-  /// any more data.
-  set didStop(VoidCallback cb);
+  /// Add a callback that will be called by the recorder when it stops recording.
+  void registerDidStop(VoidCallback cb);
 
   /// Called just before calling [SchedulerBinding.handleDrawFrame].
   void frameWillDraw();
@@ -998,9 +1005,9 @@ class _RecordingWidgetsBinding extends BindingBase
     }
     final FlutterExceptionHandler originalOnError = FlutterError.onError;
 
-    recorder.didStop = () {
+    recorder.registerDidStop(() {
       _benchmarkStopped = true;
-    };
+    });
 
     // Fail hard and fast on errors. Benchmarks should not have any errors.
     FlutterError.onError = (FlutterErrorDetails details) {