Repository: flutter
Issue: Multibyte Texts are taller than alphabet Texts even though they are same FontSize
Labels: engine,a: internationalization,a: typography,has reproducible steps,P2,found in release: 3.3,found in release: 3.6,team-engine,triaged-engine

## Steps to Reproduce

Texts of emoji and Japanese is taller than the Texts of the alphabet.

**Expected results:** <!-- what did you want to see? -->

Same height.

**Actual results:** <!-- what did you see? -->

iOS 13.5

<img width="294" alt="スクリーンショット 2020-05-25 11 31 58" src="https://user-images.githubusercontent.com/1098127/82772944-b8fd5e80-9e7b-11ea-9929-cd47af3a564f.png">

<details>

```dart
import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Text heights',
      home: HomePage(),
    );
  }
}

class HomePage extends StatefulWidget {
  @override
  HomePageState createState() => HomePageState();
}

class HomePageState extends State<HomePage> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("Text box heights"),
      ),
      body: Column(
        children: <Widget>[
          Container(
            padding: const EdgeInsets.all(20.0),
            child: Row(
              children: <Widget>[
                Container(
                  color: Colors.red,
                  child: Text(
                    "ABC",
                  ),
                ),
                Container(
                  color: Colors.green,
                  child: Text(
                    "あいう",
                  ),
                ),
              ],
            ),
          ),
          Container(
            padding: const EdgeInsets.all(20.0),
            child: Row(
              children: <Widget>[
                Container(
                  color: Colors.red,
                  child: Text(
                    "ABC",
                  ),
                ),
                Container(
                  color: Colors.blue,
                  child: Text(
                    "😀😀😀",
                  ),
                ),
              ],
            ),
          ),
        ],
      ),
    );
  }
}
```

```
[✓] Flutter (Channel dev, 1.19.0-1.0.pre, on Mac OS X 10.15.4 19E287, locale ja-JP)
    • Flutter version 1.19.0-1.0.pre at /Applications/flutter
    • Framework revision 456d80b9dd (13 days ago), 2020-05-11 11:45:03 -0400
    • Engine revision d96f962ca2
    • Dart version 2.9.0 (build 2.9.0-7.0.dev 092ed38a87)

[✓] Android toolchain - develop for Android devices (Android SDK version 29.0.3)
    • Android SDK at /Users/najeira/Library/Android/sdk
    • Platform android-29, build-tools 29.0.3
    • Java binary at: /Users/najeira/Library/Application Support/JetBrains/Toolbox/apps/AndroidStudio/ch-0/192.6392135/Android
      Studio.app/Contents/jre/jdk/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build 1.8.0_212-release-1586-b4-5784211)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 11.5)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Xcode 11.5, Build version 11E608c
    • CocoaPods version 1.9.1

[!] Android Studio (version 3.6)
    • Android Studio at /Users/najeira/Library/Application Support/JetBrains/Toolbox/apps/AndroidStudio/ch-0/192.6392135/Android Studio.app/Contents
    ✗ Flutter plugin not installed; this adds Flutter specific functionality.
    ✗ Dart plugin not installed; this adds Dart specific functionality.
    • Java version OpenJDK Runtime Environment (build 1.8.0_212-release-1586-b4-5784211)

[!] IntelliJ IDEA Ultimate Edition (version 2020.1.1)
    • IntelliJ at /Users/najeira/Applications/JetBrains Toolbox/IntelliJ IDEA Ultimate.app
    ✗ Flutter plugin not installed; this adds Flutter specific functionality.
    ✗ Dart plugin not installed; this adds Dart specific functionality.
    • For information about installing plugins, see
      https://flutter.dev/intellij-setup/#installing-the-plugins

[!] VS Code (version 1.44.2)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    ✗ Flutter extension not installed; install from
      https://marketplace.visualstudio.com/items?itemName=Dart-Code.flutter
```

</details>