Revert "[flutter_tools] remove mocks, globals from golden comparator and test runner tests (#81423)" (#81487)

This reverts commit 8fe4cc79.

e7939e091 Pause dart microtasks while UI thread is processing frame workloads (flutter/engine#25789) (#81424)

* 352a32438 Roll Skia from 421c360abe76 to 91216673f726 (1 revision) (flutter/engine#25807)

* 7171b7a5a Remove override; method no longer called (flutter/engine#25806)

* 093f66f30 Roll Skia from 91216673f726 to d1c9e52144bc (1 revision) (flutter/engine#25811)

* 36274b0dc Update firebase_testlab.sh (flutter/engine#25816)

* d5cb4738f Roll Skia from d1c9e52144bc to ffeef16664ea (4 revisions) (flutter/engine#25813)

This adds support for GestureDetector.onLongPressDown and
GestureDetector.onLongPressCancel, allowing callers to register
interest in the initial pointer contact that might turn into
a long-press (and the associated cancel event if the gesture
loses).

This reverts commit 437ff210.

It was incorrectly resetting state when it received a
non-allowed pointer but had already accepted a gesture.

https://github.com/flutter/flutter/issues/81339

* fix PointerUpEvent conversion PointerMoveEvent needs to use the default buttons value.(#73286)

* feat PointerMoveEvent conversion adds test cases

* fix event conversion may modify the original buttons value.

* Update packages/flutter/lib/src/gestures/resampler.dart
Co-authored-by: David Reveman <dreveman@gmail.com>

d6f50f4fe Roll Skia from be1c99658979 to b7223e1269f2 (12 revisions) (flutter/engine#25794) (#81349)