Repository: flutter
Issue: ScrollAction slows down significantly when holding down keys
Labels: framework,f: scrolling,platform-web,a: desktop,P2,team-framework,triaged-framework

### Steps to reproduce

1. Place a [`MaterialApp`](https://api.flutter.dev/flutter/material/MaterialApp-class.html) widget at the root of your widget tree.
2. Place any scrollable widget below the [`MaterialApp`](https://api.flutter.dev/flutter/material/MaterialApp-class.html) and make sure it uses the [`PrimaryScrollController`](https://api.flutter.dev/flutter/widgets/PrimaryScrollController-class.html).
3. Try scrolling down by pressing ctrl+down for desktop or just the down arrow for web.
4. Then try doing the same, but holding the keys down.

### Expected results

I would expect to scroll faster when holding down the keys than when pressing them repeatedly.

### Actual results

Scrolling becomes significantly slower when holding down the keys compared to pressing them repeatedly.

### Code sample

<details open><summary>Code sample</summary>

```dart
import 'package:flutter/material.dart';

void main() => runApp(const ExampleApp());

class ExampleApp extends StatelessWidget {
  const ExampleApp({super.key});

  @override
  Widget build(BuildContext context) => MaterialApp(
        home: Scaffold(
          body: ListView.builder(
            primary: true,
            itemCount: 15,
            itemBuilder: (BuildContext context, int index) => Container(
              color: Colors.primaries[index],
              height: 150,
              child: Center(
                child: Text(
                  'Entry $index',
                  style: Theme.of(context).textTheme.headlineMedium,
                ),
              ),
            ),
          ),
        ),
      );
}
```

</details>


### Screenshots or Video

<details open>
<summary>Screenshots / Video demonstration</summary>

The first part shows the behavior when pressing the scroll keys repeatedly, and then while holding the scroll keys down.

![ScrollAction Bug Demo](https://github.com/user-attachments/assets/aeb7f07f-a5b6-408f-aa89-394a3c9a2319)

</details>


### Logs

_No response_

### Flutter Doctor output

<details open><summary>Doctor output</summary>

```console
[✓] Flutter (Channel stable, 3.24.5, on Fedora Linux 41 (Workstation Edition) 6.11.7-300.fc41.x86_64, locale
    en_US.UTF-8)
    • Flutter version 3.24.5 on channel stable at /home/kamil/.local/apps/flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision dec2ee5c1f (7 days ago), 2024-11-13 11:13:06 -0800
    • Engine revision a18df97ca5
    • Dart version 3.5.4
    • DevTools version 2.37.3

[✗] Android toolchain - develop for Android devices
    ✗ Unable to locate Android SDK.
      Install Android Studio from: https://developer.android.com/studio/index.html
      On first launch it will assist you in installing the Android SDK components.
      (or visit https://flutter.dev/to/linux-android-setup for detailed instructions).
      If the Android SDK has been installed to a custom location, please use
      `flutter config --android-sdk` to update to that location.


[✓] Chrome - develop for the web
    • CHROME_EXECUTABLE = /usr/bin/brave-browser-stable

[✓] Linux toolchain - develop for Linux desktop
    • clang version 19.1.0 (Fedora 19.1.0-1.fc41)
    • cmake version 3.30.5
    • ninja version 1.12.1
    • pkg-config version 2.3.0

[!] Android Studio (not installed)
    • Android Studio not found; download from https://developer.android.com/studio/index.html
      (or visit https://flutter.dev/to/linux-android-setup for detailed instructions).

[✓] VS Code (version 1.95.3)
    • VS Code at /usr/share/code
    • Flutter extension version 3.100.0

[✓] Connected device (2 available)
    • Linux (desktop) • linux  • linux-x64      • Fedora Linux 41 (Workstation Edition) 6.11.7-300.fc41.x86_64
    • Chrome (web)    • chrome • web-javascript • Brave Browser 131.1.73.89

[✓] Network resources
    • All expected network resources are available.

! Doctor found issues in 2 categories.
```

</details>