_MaterialAppState should dispose MaterialHeroController. (#133951)

packages/flutter/lib/src/material/app.dart

@@ -880,6 +880,12 @@ class _MaterialAppState extends State<MaterialApp> {
     _heroController = MaterialApp.createMaterialHeroController();
   }
 
+  @override
+  void dispose() {
+    _heroController.dispose();
+    super.dispose();
+  }
+
   // Combine the Localizations for Material with the ones contributed
   // by the localizationsDelegates parameter, if any. Only the first delegate
   // of a particular LocalizationsDelegate.type is loaded so the

packages/flutter/lib/src/widgets/heroes.dart

@@ -612,6 +612,19 @@ class _HeroFlight {
     navigator.userGestureInProgressNotifier.addListener(delayedPerformAnimationUpdate);
   }
 
+  /// Releases resources.
+  @mustCallSuper
+  void dispose() {
+    if (overlayEntry != null) {
+      overlayEntry!.remove();
+      overlayEntry!.dispose();
+      overlayEntry = null;
+      _proxyAnimation.parent = null;
+      _proxyAnimation.removeListener(onTick);
+      _proxyAnimation.removeStatusListener(_handleAnimationUpdate);
+    }
+  }
+
   void onTick() {
     final RenderBox? toHeroBox = (!_aborted && manifest.toHero.mounted)
       ? manifest.toHero.context.findRenderObject() as RenderBox?
@@ -1027,6 +1040,14 @@ class HeroController extends NavigatorObserver {
       },
     );
   }
+
+  /// Releases resources.
+  @mustCallSuper
+  void dispose() {
+    for (final _HeroFlight flight in _flights.values) {
+      flight.dispose();
+    }
+  }
 }
 
 /// Enables or disables [Hero]es in the widget subtree.

packages/flutter/test/material/snack_bar_test.dart

@@ -14,6 +14,7 @@ import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter_test/flutter_test.dart';
+import 'package:leak_tracker_flutter_testing/leak_tracker_flutter_testing.dart';
 
 void main() {
   testWidgets('SnackBar control test', (WidgetTester tester) async {
@@ -2542,7 +2543,9 @@ void main() {
     expect(find.text(secondHeader), findsOneWidget);
   });
 
-  testWidgets('Should have only one SnackBar during back swipe navigation', (WidgetTester tester) async {
+  testWidgetsWithLeakTracking('Should have only one SnackBar during back swipe navigation',
+  leakTrackingTestConfig: LeakTrackingTestConfig.debugNotDisposed(),
+  (WidgetTester tester) async {
     const String snackBarText = 'hello snackbar';
     const Key snackTarget = Key('snack-target');
     const Key transitionTarget = Key('transition-target');

packages/flutter/test/material/switch_list_tile_test.dart

@@ -865,7 +865,7 @@ void main() {
     );
   });
 
-  testWidgets('Material3 - SwitchListTile respects thumbColor in hovered/pressed states', (WidgetTester tester) async {
+  testWidgetsWithLeakTracking('Material3 - SwitchListTile respects thumbColor in hovered/pressed states', (WidgetTester tester) async {
     tester.binding.focusManager.highlightStrategy = FocusHighlightStrategy.alwaysTraditional;
     const Color hoveredThumbColor = Color(0xFF4caf50);
     const Color pressedThumbColor = Color(0xFFF44336);