Attempt to fix memory screen goldens

Author: elliette

packages/devtools_app/test/screens/memory/framework/memory_screen_test.dart

@@ -63,14 +63,23 @@ void main() {
   }
 
   Future<void> pumpMemoryScreen(WidgetTester tester) async {
-    await tester.pumpWidget(
-      wrapWithControllers(const MemoryScreenBody(), memory: controller),
-    );
+    await tester.runAsync(() async {
+      await tester.pumpWidget(
+        wrapWithControllers(const MemoryScreenBody(), memory: controller),
+      );
 
-    // Delay to ensure the memory profiler has collected data.
-    await tester.runAsync(
-      () async => await tester.pumpAndSettle(const Duration(seconds: 2)),
-    );
+      // Current workaround for flaky image asset testing.
+      // See: https://github.com/flutter/flutter/issues/38997
+      for (final element in find.byType(Image).evaluate()) {
+        final widget = element.widget as Image;
+        final image = widget.image;
+        await precacheImage(image, element);
+        await tester.pumpAndSettle();
+      }
+
+      // Delay to ensure the memory profiler has collected data.
+      await tester.pumpAndSettle(const Duration(seconds: 2));
+    });
     expect(find.byType(MemoryScreenBody), findsOneWidget);
   }