Repository: flutter
Issue: [Web][iOS][Safari]: Free space is shown at the bottom of screen when focussing a textfield
Labels: a: text input,framework,a: quality,platform-web,e: OS-version specific,a: layout,assigned for triage,P2,browser: safari-ios,team-web,triaged-web

## Steps to Reproduce

<!-- Please include full steps to reproduce so that we can reproduce the problem. -->

1. Execute `flutter run -d chrome` on the code sample <!-- (see "Code sample" section below) -->
2. Open the local website on an iOS Simulator in Safari
3. Click in the textfield.
4. Observe the bottom area of the screen

**Expected results:**
I expected the yellow area to expand.

**Actual results:**
A blue bar appears. This area will never go away, not even after leaving the textfield or navigating to a new screen.

![safari demo](https://user-images.githubusercontent.com/89379862/145579635-004d0b98-baef-4a50-8209-fd4ee5fc4d5a.gif)

<details>
It is pretty bad 
<summary>Code sample</summary>

```dart
import 'package:flutter/material.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: const Scaffold(
        backgroundColor: Colors.yellow,
        body: Center(
          child: TextField(),
        ),
      ),
    );
  }
}

```

</details>

<details>
  <summary>Logs</summary>

Sadly there are no logs when opening flutter web from ios simulator.

```
No issues found! (ran in 2.0s)
```

<!-- Finally, paste the output of running `flutter doctor -v` here. -->

```
[✓] Flutter (Channel stable, 2.8.0, on macOS 12.0.1 21A559 darwin-arm, locale en-DE)
    • Flutter version 2.8.0 at /opt/homebrew/Caskroom/flutter/2.5.3/flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision cf44000065 (2 days ago), 2021-12-08 14:06:50 -0800
    • Engine revision 40a99c5951
    • Dart version 2.15.0

[✓] Android toolchain - develop for Android devices (Android SDK version 31.0.0-rc5)
    • Android SDK at /Users/bweber/Library/Android/sdk
    • Platform android-31, build-tools 31.0.0-rc5
    • Java binary at: /opt/homebrew/opt/openjdk/bin/java
    • Java version OpenJDK Runtime Environment Homebrew (build 17+0)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 13.1)
    • 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
    • Android Studio at /Users/bweber/Library/Application
      Support/JetBrains/Toolbox/apps/AndroidStudio/ch-2/212.5457.46.2112.7905983/And
      roid Studio Preview.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
    ✗ Unable to find bundled Java version.
    • Try updating or re-installing Android Studio.

[!] Android Studio
    • Android Studio at /Users/bweber/Library/Application
      Support/JetBrains/Toolbox/apps/AndroidStudio/ch-2/212.5284.40.2112.7855545/And
      roid Studio Preview.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
    ✗ Unable to find bundled Java version.
    • Try updating or re-installing Android Studio.

[✓] VS Code (version 1.63.0)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.29.0

[✓] Connected device (5 available)
    • FP3 (mobile)           • A209HADM0202                         • android-arm64
      • Android 10 (API 29)
    • iPad (2) (mobile)      • 00008020-000E20311A29402E            • ios
      • iOS 14.8.1 18H107
    • iPhone 8 Plus (mobile) • 8F31D98F-D219-4F30-B1CB-0D8D6B7A8494 • ios
      • com.apple.CoreSimulator.SimRuntime.iOS-15-0 (simulator)
    • macOS (desktop)        • macos                                • darwin-arm64
      • macOS 12.0.1 21A559 darwin-arm
    • Chrome (web)           • chrome                               • web-javascript
      • Google Chrome 96.0.4664.93
    ! Error: iPad (2) is busy: Fetching debug symbols for iPad (2). Xcode will
      continue when iPad (2) is finished. (code -10)
    ! Error: MyRealiPhone is not connected. Xcode will continue when MyRealiPhone is
      connected. (code -13)

! Doctor found issues in 2 categories.
```

</details>