Flutter web compositor memory leak

main.dart

// Copyright 2019 the Dart project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license
// that can be found in the LICENSE file.

import 'package:flutter/material.dart';
import 'dart:js_interop';

void main() => runApp(const MyApp());

@JS('window.flutterCanvasKit.HEAP8.byteLength')
external JSNumber get _canvasKitMemory;

int getMemoryUsageBytes() {
  return _canvasKitMemory.toDartInt;
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        colorSchemeSeed: Colors.blue,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  final String title;

  const MyHomePage({
    super.key,
    required this.title,
  });

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  void _incrementCounter() {
    setState(() {
      _counter++;
    });
  }

  @override
  void initState() {
    super.initState();
    queueFrame();
  }

  void queueFrame() {
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (!mounted) {
      } else {
        _incrementCounter();
        queueFrame();
      }
    });
  }

  final focusNodes = List.generate(500, (x) => FocusNode());

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Expanded(
                child: Stack(children: [
              for (var focusNode in focusNodes)
                Positioned(
                    top: 15.0 * focusNodes.indexOf(focusNode),
                    left: 15.0 * focusNodes.indexOf(focusNode),
                    child: Container(
                        decoration: BoxDecoration(
                            color:
                                Color.fromARGB(0xff, _counter % 255, 255, 255)),
                        width: 400,
                        height: 400,
                        clipBehavior: Clip.antiAlias,
                        child: SelectableRegion(
                            focusNode: focusNode,
                            selectionControls: materialTextSelectionControls,
                            child: Text(
                              'memory: ${getMemoryUsageBytes() / 1024 / 1024}MB $_counter ${focusNodes.indexOf(focusNode)}',
                              style: Theme.of(context).textTheme.bodySmall,
                            )))),
            ]))
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: const Icon(Icons.add),
      ),
    );
  }
}