Repository: flutter
Issue: [iOS][Snapshotting] Snapshotting a view that has not been rendered at least once requires afterScreenUpdates:YES.
Labels: a: text input,platform-ios,has reproducible steps,P2,found in release: 2.10,found in release: 2.13,team-ios,triaged-ios

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When I tried to make the text input of a text field start with a capital letter by default and tested it on a physical iOS device, I got the following message in the debug console, after calling `TextEditingController().clear()`:
```
[Snapshotting] Snapshotting a view (0x104e3dd80, _UIReplicantView) that has not been rendered at least once requires afterScreenUpdates:YES.
```


## Steps to Reproduce

<!-- You must include full steps to reproduce so that we can reproduce the problem. -->

1. Run `flutter create bug`.
2. Update the `main.dart` as follows: .
```dart
import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatelessWidget {
  final controller = TextEditingController();
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            TextField(
              controller: controller,
              textCapitalization: TextCapitalization.sentences,
            ),
            TextButton(
              onPressed: controller.clear,
              child: Text('Clear TextField'),
            ),
          ],
        ),
      ),
    );
  }
}

```
3. Run the App on a physical iOS device
Type anything into the text field and press `Clear TextField` which calls `TextEditingController().clear()`

**Expected results:** <!-- what did you want to see? -->
A cleared TextField.
**Actual results:** <!-- what did you see? -->
A cleared Textfield and a message in the debug-console saying:
```
[Snapshotting] Snapshotting a view (0x104e3dd80, _UIReplicantView) that has not been rendered at least once requires afterScreenUpdates:YES.
```
<details>
  <summary>Flutter doctor -v</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
      exception, please see if the error message includes enough information
      to explain how to solve the issue.
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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 beta, 1.26.0-17.6.pre, on macOS 11.2.1 20D74 darwin-x64, locale en-DE)
    • Flutter version 1.26.0-17.6.pre at /Users/fynnlemburg/development/flutter
    • Framework revision a29104a69b (9 days ago), 2021-02-16 09:26:56 -0800
    • Engine revision 21fa8bb99e
    • Dart version 2.12.0 (build 2.12.0-259.12.beta)

[✓] Android toolchain - develop for Android devices (Android SDK version 29.0.2)
    • Android SDK at /Users/fynnlemburg/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 1.10.0

[✓] 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 1.53.2)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.19.0

[✓] Connected device (1 available)
    • Chrome (web) • chrome • web-javascript • Google Chrome 88.0.4324.192

• No issues found!
```

</details>