dispose image when cache clear (#76600)

packages/flutter/lib/src/painting/image_cache.dart

@@ -188,6 +188,9 @@ class ImageCache {
         },
       );
     }
+    for (final _CachedImage image in _cache.values) {
+      image.dispose();
+    }
     _cache.clear();
     _pendingImages.clear();
     _currentSizeBytes = 0;

packages/flutter/test/widgets/scroll_aware_image_provider_test.dart

@@ -34,7 +34,7 @@ void main() {
     await tester.pumpWidget(TestWidget(key));
 
     final DisposableBuildContext context = DisposableBuildContext(key.currentState!);
-    final TestImageProvider testImageProvider = TestImageProvider(testImage);
+    final TestImageProvider testImageProvider = TestImageProvider(testImage.clone());
     final ScrollAwareImageProvider<TestImageProvider> imageProvider = ScrollAwareImageProvider<TestImageProvider>(
       context: context,
       imageProvider: testImageProvider,
@@ -69,7 +69,7 @@ void main() {
     ));
 
     final DisposableBuildContext context = DisposableBuildContext(key.currentState!);
-    final TestImageProvider testImageProvider = TestImageProvider(testImage);
+    final TestImageProvider testImageProvider = TestImageProvider(testImage.clone());
     final ScrollAwareImageProvider<TestImageProvider> imageProvider = ScrollAwareImageProvider<TestImageProvider>(
       context: context,
       imageProvider: testImageProvider,
@@ -109,7 +109,7 @@ void main() {
     ));
 
     final DisposableBuildContext context = DisposableBuildContext(keys.last.currentState!);
-    final TestImageProvider testImageProvider = TestImageProvider(testImage);
+    final TestImageProvider testImageProvider = TestImageProvider(testImage.clone());
     final ScrollAwareImageProvider<TestImageProvider> imageProvider = ScrollAwareImageProvider<TestImageProvider>(
       context: context,
       imageProvider: testImageProvider,
@@ -166,7 +166,7 @@ void main() {
     ));
 
     final DisposableBuildContext context = DisposableBuildContext(keys.last.currentState!);
-    final TestImageProvider testImageProvider = TestImageProvider(testImage);
+    final TestImageProvider testImageProvider = TestImageProvider(testImage.clone());
     final ScrollAwareImageProvider<TestImageProvider> imageProvider = ScrollAwareImageProvider<TestImageProvider>(
       context: context,
       imageProvider: testImageProvider,
@@ -233,7 +233,7 @@ void main() {
     ));
 
     final DisposableBuildContext context = DisposableBuildContext(keys.last.currentState!);
-    final TestImageProvider testImageProvider = TestImageProvider(testImage);
+    final TestImageProvider testImageProvider = TestImageProvider(testImage.clone());
     final ScrollAwareImageProvider<TestImageProvider> imageProvider = ScrollAwareImageProvider<TestImageProvider>(
       context: context,
       imageProvider: testImageProvider,
@@ -298,7 +298,7 @@ void main() {
     ));
 
     final DisposableBuildContext context = DisposableBuildContext(key.currentState!);
-    final TestImageProvider testImageProvider = TestImageProvider(testImage);
+    final TestImageProvider testImageProvider = TestImageProvider(testImage.clone());
     final ScrollAwareImageProvider<TestImageProvider> imageProvider = ScrollAwareImageProvider<TestImageProvider>(
       context: context,
       imageProvider: testImageProvider,
@@ -349,7 +349,7 @@ void main() {
     ));
 
     final DisposableBuildContext context = DisposableBuildContext(key.currentState!);
-    final TestImageProvider testImageProvider = TestImageProvider(testImage);
+    final TestImageProvider testImageProvider = TestImageProvider(testImage.clone());
     final ScrollAwareImageProvider<TestImageProvider> imageProvider = ScrollAwareImageProvider<TestImageProvider>(
       context: context,
       imageProvider: testImageProvider,