Repository: flutter
Issue: [web] [html-renderer] BlurStyle on BoxShadow doesn't work
Labels: engine,platform-web,e: web_html,has reproducible steps,P2,found in release: 2.10,found in release: 2.11,team-web,triaged-web

## Steps to Reproduce

1. Execute `flutter run --html-renderer html` on the code sample.
2. See how the BlurStyle on the BoxShadow is not applied.
3. Try different values for the BlurStyle and see that none of them work, and it always uses the `normal` style.

Note:
* This works fine using the CanvasKit renderer.
* I'm testing it on macOS using Chrome.

**Expected results:** <!-- what did you want to see? -->
The one in the code sample:
<img width="300" alt="Screen Shot 2022-02-24 at 9 49 36 AM" src="https://user-images.githubusercontent.com/29583601/155580432-b8785b74-6af7-4027-9163-983134e2a5c7.png">
Using other BlurStyle values:
<img width="300" alt="Screen Shot 2022-02-24 at 9 49 48 AM" src="https://user-images.githubusercontent.com/29583601/155580553-9e2913c9-f606-4426-b478-d7e43d91859c.png">
<img width="300" alt="Screen Shot 2022-02-24 at 9 50 03 AM" src="https://user-images.githubusercontent.com/29583601/155580562-043097f3-e07f-4cc0-bfe9-5b659dee3044.png">

**Actual results:** <!-- what did you see? -->
For all BlurStyle values:
<img width="300" alt="Screen Shot 2022-02-24 at 9 48 11 AM" src="https://user-images.githubusercontent.com/29583601/155580457-3792ca67-d2cb-472d-9dbc-d86680c44f34.png">

<details>
<summary>Code sample</summary>

```dart
void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);
  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      home: BugReportPage(),
    );
  }
}

class BugReportPage extends StatelessWidget {
  const BugReportPage({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Material(
      color: Colors.white,
      child: Center(
        child: Container(
          width: 200,
          height: 200,
          decoration: const BoxDecoration(
            color: Colors.white30,
            boxShadow: [
              BoxShadow(
                color: Colors.black45,
                blurRadius: 30,
                blurStyle: BlurStyle.outer,
              ),
            ],
          ),
        ),
      ),
    );
  }
}
```

</details>

<details>
  <summary>Logs</summary>

`flutter run --verbose`:
[No logs were found between backlits]

`flutter analyze`:
```
Analyzing reproduction_project...                                       
No issues found! (ran in 1.4s)
```

`flutter doctor -v`:
```
[✓] Flutter (Channel stable, 2.10.2, on macOS 12.1 21C52 darwin-x64, locale en-US)
    • Flutter version 2.10.2 at /Users/behnamsattar/tools/bin/flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision 097d3313d8 (6 days ago), 2022-02-18 19:33:08 -0600
    • Engine revision a83ed0e5e3
    • Dart version 2.16.1
    • DevTools version 2.9.2

[!] Android toolchain - develop for Android devices (Android SDK version 30.0.3)
    • Android SDK at /Users/behnamsattar/Library/Android/sdk
    ✗ cmdline-tools component is missing
      Run `path/to/sdkmanager --install "cmdline-tools;latest"`
      See https://developer.android.com/studio/command-line for more details.
    ✗ Android license status unknown.
      Run `flutter doctor --android-licenses` to accept the SDK licenses.
      See https://flutter.dev/docs/get-started/install/macos#android-setup for more details.

[✓] Xcode - develop for iOS and macOS (Xcode 13.2.1)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • CocoaPods version 1.11.2

[✓] Chrome - develop for the web
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 2020.3)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 11.0.10+0-b96-7281165)

[✓] VS Code (version 1.64.2)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.34.0

[✓] Connected device (1 available)
    • Chrome (web) • chrome • web-javascript • Google Chrome 98.0.4758.109

[✓] HTTP Host Availability
    • All required HTTP hosts are available

! Doctor found issues in 1 category.
```

</details>