Issue 1:
Steps to Reproduce

Device: OnePlus 6T, Android 9

Click on FlatButton with 3 fingers

FlatButton changes colors and crash in background

Logs

E/flutter ( 5777): [ERROR:flutter/shell/common/shell.cc(184)] Dart Error: Unhandled exception:
E/flutter ( 5777): NoSuchMethodError: The getter 'lastPosition' was called on null.
E/flutter ( 5777): Receiver: null
E/flutter ( 5777): Tried calling: lastPosition
E/flutter ( 5777): #0 PointerEventConverter.expand (package:flutter/src/gestures/converter.dart:251)
E/flutter ( 5777): #1 _SyncIterator.moveNext (dart:core/runtime/libcore_patch.dart:151)
E/flutter ( 5777): #2 ListQueue.addAll (dart:collection/queue.dart:715)
E/flutter ( 5777): #3 _WidgetsFlutterBinding&BindingBase&GestureBinding._handlePointerDataPacket (package:flutter/src/gestures/binding.dart:83)
E/flutter ( 5777): #4 _invoke1 (dart:ui/hooks.dart:168)
E/flutter ( 5777): #5 _dispatchPointerDataPacket (dart:ui/hooks.dart:122)

Running "flutter packages get" in flutter_tools... 1.9s
Analyzing flutter_tools...
No issues found! (ran in 42.0s)

[√] Flutter (Channel stable, v1.0.0, on Microsoft Windows [Version 10.0.17134.137], locale en-GB)
• Flutter version 1.0.0 at D:\src\flutter
• Framework revision 5391447fae (10 days ago), 2018-11-29 19:41:26 -0800
• Engine revision 7375a0f414
• Dart version 2.1.0 (build 2.1.0-dev.9.4 f9ebf21297)

[√] Android toolchain - develop for Android devices (Android SDK 28.0.3)
• Android SDK at C:\Users\vuk.vasic\AppData\Local\Android\sdk
• Android NDK location not configured (optional; useful for native profiling support)
• Platform android-28, build-tools 28.0.3
• Java binary at: C:\Program Files\Android\Android Studio\jre\bin\java
• Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1024-b02)
• All Android licenses accepted.

[√] Android Studio (version 3.1)
• Android Studio at C:\Program Files\Android\Android Studio
• Flutter plugin version 29.0.1
• Dart plugin version 173.4700
• Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1024-b02)

[√] VS Code, 64-bit edition (version 1.29.1)
• VS Code at C:\Program Files\Microsoft VS Code
• Flutter extension version 2.21.1

[√] Connected device (1 available)
• ONEPLUS A6013 • 660683c4 • android-arm64 • Android 9 (API 28)

• No issues found!

Issue 2:
Internal: b/143427192

On our released version of App, we were notified with an exception as the title show, the detail track infos are as follow:

NoSuchMethodError: The getter 'lastPosition' was called on null.

6 Receiver: null
7 Tried calling: lastPosition===>#0 PointerEventConverter.expand (package:flutter/src/gestures/converter.dart:246)
8 #1 _SyncIterator.moveNext (dart:core/runtime/libcore_patch.dart:151)
9 #2 ListQueue.addAll (dart:collection/queue.dart:715)
10 #3 _WidgetsFlutterBinding&BindingBase&GestureBinding._handlePointerDataPacket (package:flutter/src/gestures/binding.dart:46)
11 #4 _rootRunUnary (dart:async/zone.dart:1136)
12 #5 _CustomZone.runUnary (dart:async/zone.dart:1029)
13 #6 _CustomZone.runUnaryGuarded (dart:async/zone.dart:931)
14 #7 _invoke1 (dart:ui/hooks.dart:144)
15 #8 _dispatchPointerDataPacket (dart:ui/hooks.dart:99)

That's the full exception stack, from where I cannot get any info where my code got wrong because it's all about the framework layer, and I'm not very familiar with this layer.I did not found anything invoke the function _dispatchPointerDataPacket in hooks.dart from my code.

This exception appeared only once by now.

Can we avoid this by checking if it's null before invoking lastPosition in converter.dart ?