fix: replay not saved during animations (#2518)

flutter/lib/src/replay/replay_recorder.dart

@@ -1,7 +1,6 @@
 import 'dart:async';
 import 'dart:developer';
 
-import 'package:flutter/scheduler.dart';
 import 'package:meta/meta.dart';
 
 import '../screenshot/recorder.dart';
@@ -18,9 +17,7 @@ class ReplayScreenshotRecorder extends ScreenshotRecorder {
   @override
   @protected
   Future<void> executeTask(void Function() task, Flow flow) {
-    // Schedule the task to run between frames, when the app is idle.
-    return options.bindingUtils.instance
-            ?.scheduleTask<void>(task, Priority.idle, flow: flow) ??
-        Future.sync(task);
+    // Future() schedules the task to be executed asynchronously with TImer.run.
+    return Future(task);
   }
 }

flutter/lib/src/screenshot/recorder.dart

@@ -111,8 +111,11 @@ class ScreenshotRecorder {
   }
 
   @protected
-  Future<void> executeTask(void Function() task, Flow flow) =>
-      Future.sync(task);
+  Future<void> executeTask(void Function() task, Flow flow) {
+    // Future.sync() starts executing the function synchronously, until the
+    // first await, i.e. it's the same as if the code was executed directly.
+    return Future.sync(task);
+  }
 
   List<WidgetFilterItem>? _obscureSync(_Capture<dynamic> capture) {
     if (_maskingConfig != null) {

flutter/test/screenshot/recorder_test.dart

@@ -83,7 +83,7 @@ void main() async {
       });
 
     expect(
-        fixture.capture(),
+        fixture.capture,
         throwsA(predicate(
             (Exception e) => e.toString().contains('testing masking error'))));
   });
@@ -130,23 +130,18 @@ class _Fixture {
       ScreenshotRecorderConfig(width: width, height: height), options);
   late final options = defaultTestOptions()
     ..bindingUtils = TestBindingWrapper();
-  final WidgetTester _tester;
   final double? width;
   final double? height;
 
-  _Fixture(this._tester, {this.width, this.height});
+  _Fixture({this.width, this.height});
 
   static Future<_Fixture> create(WidgetTester tester,
       {double? width, double? height}) async {
-    final fixture = _Fixture(tester, width: width, height: height);
+    final fixture = _Fixture(width: width, height: height);
     await pumpTestElement(tester);
     return fixture;
   }
 
-  Future<String?> capture() async {
-    final future = sut.capture<String?>(
-        (Image image) => Future.value("${image.width}x${image.height}"));
-    await _tester.idle();
-    return future;
-  }
+  Future<String?> capture() => sut.capture<String?>(
+      (Image image) => Future.value("${image.width}x${image.height}"));
 }