Repository: flutter
Issue: [iOS] Holding down Backspace key on hardware keyboard doesn't keep deleting characters in iOS Simulator
Labels: a: text input,platform-ios,framework,has reproducible steps,P2,found in release: 2.8,found in release: 2.9,found in release: 2.10,team-ios,triaged-ios

## Steps to Reproduce

<!-- Please include full steps to reproduce so that we can reproduce the problem. -->

1. Run the app using code below on an iOS simulator (iPhone 8 running iOS 14.5) and type something in the field
2. Then press the backspace button on hardware keyboard and keep it pressed.

**Expected results:** <!-- what did you want to see? -->
The characters should keep getting deleted while holding the backspace button

**Actual results:** <!-- what did you see? -->
Only one character gets deleted

This used to work in flutter 2.0.1, but no longer works in 2.8.1 (I haven't tried with 2.5)

<details>
<summary>Code sample</summary>

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      we regretfully will have to close it.
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```dart
import 'package:flutter/material.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({Key? key, required this.title}) : super(key: key);

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  void _incrementCounter() {
    setState(() {
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            const Text(
              'You have pushed the button this many times:',
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.headline4,
            ),
            TextField(),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: const Icon(Icons.add),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}
```

</details>

<details>
  <summary>Logs</summary>

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      Run your application with `flutter run --verbose` and attach all the
      log output below between the lines with the backticks. If there is an
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```
```

<!--
     Run `flutter analyze` and attach any output of that command below.
     If there are any analysis errors, try resolving them before filing this issue.
-->

```
```

<!-- Finally, paste the output of running `flutter doctor -v` here. -->

```
[✓] Flutter (Channel master, 2.9.0-1.0.pre.362, on macOS 11.6.1 20G224 darwin-x64, locale en-US)
    • Flutter version 2.9.0-1.0.pre.362 at /Users/danny.valente/Library/flutter/9.9.99-master
    • Upstream repository https://github.com/flutter/flutter
    • Framework revision 72df4801c8 (24 minutes ago), 2022-01-13 17:08:35 -0800
    • Engine revision f121c1fe68
    • Dart version 2.17.0 (build 2.17.0-11.0.dev)
    • DevTools version 2.9.2
```

</details>


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