Repository: flutter
Issue: MultiDragGestureRecognizers are not using local coordinates
Labels: framework,f: gestures,has reproducible steps,P2,found in release: 2.3,team-framework,triaged-framework

## Steps to Reproduce

**Expected results:** MultiDragGestureRecognizers should do the same as OneSequenceDragGestureRecognizers - respect transform and local deltas

**Actual results:** MultiDragGestureRecognizers are not respecting transforms and local deltas

<details>
  <summary>Code sample</summary>

```dart
import 'package:flutter/gestures.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(
      home: Scaffold(
        body: Home(),
      ),
    );
  }
}

class _Drag extends Drag {
  _Drag(this.onUpdate);
  final void Function(DragUpdateDetails details) onUpdate;

  @override
  void update(DragUpdateDetails details) {
    onUpdate(details);
  }
}
 
class Home extends StatefulWidget {
  Home({Key? key}) : super(key: key);

  @override
  _HomeState createState() => _HomeState();
}

class _HomeState extends State<Home> {
  static const boxWidth = 100.0;
  double pos = 0.0;

  Drag? _handleStart(Offset position) {
    return _Drag(_handleUpdate);
  }

  void _handleUpdate(DragUpdateDetails details) {
    setState(() {
      final double newPos = pos + details.delta.dx;
      pos = newPos.clamp(0.0, MediaQuery.of(context).size.width - boxWidth);
    });
  }

  double scale = 0.5;
  void switchScale() {
    setState(() {
      scale *= -1;
    });
  }

  @override
  Widget build(BuildContext context) {
    final screenSize = MediaQuery.of(context).size;
    
    return Center(
      child: Transform.scale(
        scale: scale,
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            IconButton(
              icon: const Icon(
                Icons.rotate_right,
                size: 40,
              ),
              onPressed: switchScale,
            ),
            const SizedBox(height: 16.0),
            RawGestureDetector(
              gestures: {

                // Actual

                HorizontalMultiDragGestureRecognizer: GestureRecognizerFactoryWithHandlers<HorizontalMultiDragGestureRecognizer>(
                  () => HorizontalMultiDragGestureRecognizer(),
                  (HorizontalMultiDragGestureRecognizer instance) => instance
                    ..onStart = _handleStart,
                ),

                // Expected

                HorizontalDragGestureRecognizer: GestureRecognizerFactoryWithHandlers<HorizontalDragGestureRecognizer>(
                  () => HorizontalDragGestureRecognizer(),
                  (HorizontalDragGestureRecognizer instance) => instance
                    ..onUpdate = _handleUpdate,
                ),
              },
              child: Container(
                width: screenSize.width,
                height: 200.0,
                color: Colors.blue,
                child: Align(
                  alignment: Alignment.centerLeft,
                  child: Container(
                    margin: EdgeInsets.only(left: pos),
                    width: boxWidth,
                    height: 200.0,
                    color: Colors.red,
                  ),
                ),
              ),
            ),
          ],
        ),
      ),
    );
  }
}
```
</details>

<details>
  <summary>Logs</summary>

```
n/a
```

```
Analyzing issues...

   info - The declaration '_handleStart' isn't referenced - lib\main.dart:45:9 - unused_element
   info - Unused import: 'package:flutter_issue/main.dart' - test\widget_test.dart:2:8 - unused_import

2 issues found. (ran in 4.0s)
```

```
[√] Flutter (Channel master, 2.3.0-1.0.pre.264, on Microsoft Windows [Version 10.0.19041.928], locale ru-RU)
    • Flutter version 2.3.0-1.0.pre.264 at C:\dev\src\flutter
    • Upstream repository git@github.com:nt4f04und/flutter.git
    • Framework revision b3f7ebe069 (18 hours ago), 2021-05-08 08:54:02 +0800
    • Engine revision f57e986aa8
    • Dart version 2.14.0 (build 2.14.0-74.0.dev)

[√] Android toolchain - develop for Android devices (Android SDK version 30.0.2)
    • Android SDK at C:\Users\danya\AppData\Local\Android\sdk
    • Platform android-30, build-tools 30.0.2
    • Java binary at: C:\Program Files\Android\Android Studio\jre\bin\java
    • Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b01)
    • All Android licenses accepted.

[√] Chrome - develop for the web
    • Chrome at C:\Program Files\Google\Chrome\Application\chrome.exe

[√] Visual Studio - develop for Windows (Visual Studio Community 2019 16.7.7)
    • Visual Studio at C:\Program Files (x86)\Microsoft Visual Studio\2019\Community
    • Visual Studio Community 2019 version 16.7.30621.155
    • Windows 10 SDK version 10.0.19041.0

[√] Android Studio (version 4.1.0)
    • Android Studio at C:\Program Files\Android\Android Studio
    • 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-b01)

[√] IntelliJ IDEA Community Edition (version 2020.3)
    • IntelliJ at C:\Program Files\JetBrains\IntelliJ IDEA Community Edition 2020.3.3
    • 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

[√] VS Code (version 1.56.0)
    • VS Code at C:\Users\danya\AppData\Local\Programs\Microsoft VS Code
    • Flutter extension version 3.22.0

[√] Connected device (4 available)
    • sdk gphone x86 (mobile) • emulator-5554 • android-x86    • Android 11 (API 30) (emulator)
    • Windows (desktop)       • windows       • windows-x64    • Microsoft Windows [Version 10.0.19041.928]
    • Chrome (web)            • chrome        • web-javascript • Google Chrome 90.0.4430.93
    • Edge (web)              • edge          • web-javascript • Microsoft Edge 90.0.818.46

• No issues found!
```

</details>


https://user-images.githubusercontent.com/39104740/117549883-91c87e80-b045-11eb-92e4-8e31e3d2336d.mp4