Repository: flutter
Issue: [Desktop] Button's onPressed not called when mouse cursor moves while clicking
Labels: framework,f: material design,f: gestures,a: desktop,a: mouse,has reproducible steps,P2,found in release: 3.3,found in release: 3.7,team-framework,triaged-framework

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## Steps to Reproduce

<!-- You must include full steps to reproduce so that we can reproduce the problem. -->

1. Run this snippet https://dartpad.dartlang.org/e266424c9732b88c4578560dbdf7ecb6
2. Click the button to see the output in the console
3. Now click (ripple is visible), but not release while dragging the mouse cursor a bit, then release while still within the button's bounds - the onPressed callback is not executed (see gif for reference)

![CleanShot 2020-06-10 at 10 16 46](https://user-images.githubusercontent.com/16854239/84244531-0d534000-ab04-11ea-96ac-98813ff4a9bd.gif)


```dart
RaisedButton(
  child: Text(
      'Drag and release instead of single click to see that Im not working'),
  onPressed: () {
    print('clicked');
  },
  onLongPress: (){
    print('long press');
  },
),
```

**Expected results:** <!-- what did you want to see? -->

I expect my RaisedButton to behave the same way as typical HTML button (e.g. "Run" button on Dartpad). Slight movement of my cursor shouldn't cancel the action.

**Actual results:** <!-- what did you see? -->

The `onPressed` is not executed when there's a slight movement of cursor when clicking the button.

```
[✓] Flutter (Channel dev, 1.19.0-4.0.pre, on Mac OS X 10.15.5 19F101, locale pl-PL)
    • Flutter version 1.19.0-4.0.pre at /Users/dominik/fvm/versions/dev
    • Framework revision 2f7a59a8da (5 days ago), 2020-06-05 03:44:02 -0700
    • Engine revision d17c84e7af
    • Dart version 2.9.0 (build 2.9.0-13.0.dev 02915ec5ce)


[✓] Android toolchain - develop for Android devices (Android SDK version 29.0.2)
    • Android SDK at /Users/dominik/Library/Android/sdk
    • Platform android-29, build-tools 29.0.2
    • ANDROID_HOME = /Users/dominik/Library/Android/sdk
    • Java binary at: /Applications/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

[✓] Chrome - develop for the web
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 3.6)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin version 45.1.1
    • Dart plugin version 192.8052
    • Java version OpenJDK Runtime Environment (build 1.8.0_212-release-1586-b4-5784211)

[✓] VS Code (version 1.45.1)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.11.0

[✓] Connected device (3 available)
    • macOS      • macOS      • darwin-x64     • Mac OS X 10.15.5 19F101
    • Web Server • web-server • web-javascript • Flutter Tools
    • Chrome     • chrome     • web-javascript • Google Chrome 83.0.4103.97

• No issues found!
```