Repository: flutter
Issue: [web] Chrome on iOS does not hide Autofill suggestions
Labels: a: text input,engine,platform-web,has reproducible steps,P2,found in release: 2.2,found in release: 2.3,browser: safari-ios,team-web,triaged-web

Given this configuration for a `TextField` :
```dart
TextField(
    autocorrect: false,
    enableSuggestions: false,
    autofillHints: null,
    keyboardType: TextInputType.multiline,   // TextInputType.text has the same behavior
    maxLines: null,
),
```

This is how it appears on a release build on iOS browsers:

Chrome             |         Safari 
:-------------------------:|:-------------------------:
![image](https://user-images.githubusercontent.com/46427323/115117646-54258800-9fa8-11eb-9d53-4e40976def7a.png) |   ![image](https://user-images.githubusercontent.com/46427323/115117656-5a1b6900-9fa8-11eb-9ea3-c56f3b069162.png)

* for Safari, when not in private/incognito mode, it shows `autofill contact`. 

### Expected Behavior
I expected the autofill options to disappear for the given keyboard type and configuration (mainly the `keyboardType`).  


###  Pain Points:
- It takes unnecessary real estate. It becomes even worst when suggestions are enabled and  a richtext toolbar is added above it.
- It gives the wrong impression to the user when the field is not meant to be form field (e.g. messaging or social media post). 

I'm not sure what is this toolbar is called, but it seems like it's specific for form fields navigation based on the arrows and the done button. It'd be useful to either hide the entire toolbar based on the keyboardType or provide a flag to hide it. 

## Steps to Reproduce

1. Given the sample code below.
2. flutter build web --release 
3. Serve the build (e.g., `python3 -m http.server --directory build/web 8000`) 
4. Open the web app in a physical iPhone browser. (I guess the simulator browser would do too).

<details><summary>minimal sample code to reproduce</summary>

```dart
import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatelessWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  final String title;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(title),
      ),
      body: Center(
        child: SingleChildScrollView(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              TextField(
                autocorrect: false,
                enableSuggestions: false,
                autofillHints: null,
                // TextInputType.text has the same behavior
                keyboardType: TextInputType.multiline, 
                maxLines: null,
              ),
            ],
          ),
        ),
      ),
    );
  }
}

```

</details>



<details>
  <summary>flutter doctor -v output</summary>

```
[✓] Flutter (Channel stable, 2.0.4, on macOS 11.2.3 20D91 darwin-x64, locale en)
    • Flutter version 2.0.4 at /Users/osaxma/fvm/versions/stable
    • Framework revision b1395592de (2 weeks ago), 2021-04-01 14:25:01 -0700
    • Engine revision 2dce47073a
    • Dart version 2.12.2

[✓] Android toolchain - develop for Android devices (Android SDK version 29.0.2)
    • Android SDK at /Users/osaxma/Library/Android/sdk
    • Platform android-30, build-tools 29.0.2
    • Java binary at: /Applications/Android Studio.app/Contents/jre/jdk/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6915495)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Xcode 12.4, Build version 12D4e
    • CocoaPods version 1.10.1

[✓] Chrome - develop for the web
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 4.1)
    • 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 1.8.0_242-release-1644-b3-6915495)

[✓] VS Code (version 1.55.2)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.21.0

[✓] Connected device (2 available)
    • macOS (desktop) • macos  • darwin-x64     • macOS 11.2.3 20D91 darwin-x64
    • Chrome (web)    • chrome • web-javascript • Google Chrome 89.0.4389.128

• No issues found!
```

</details>