Fixes https://github.com/flutter/flutter/issues/142045

The intent of using `??=` was that if the tooltip is already scheduled for showing, rescheduling another show does nothing. But if the tooltip is already scheduled for dismissing, the `??=` won't cancel the dismiss timer and as a result the tooltip won't show. So the `??=` is now replaced by `=` to keep it consistent with the `_scheduleDismissTooltip` implementation.

Revert "[web] - Fix broken `TextField` in semantics mode when it's a sibling of `Navigator`" (#142129)

Reverts flutter/flutter#138446

b/322136071

When a `TextField` is rendered before a `Navigator`, it breaks in semantics mode.  This is because the framework generates the incorrect semantics tree (excludes the TextField) and when that tree gets sent to the engine, we don't get the signal to create the corresponding `<input>` element.

This happens for a few reasons:
* `ModalBarrier` uses `BlockSemantics` to drop the semantics of routes beneath the current route in `Navigator`
* `ModalBarrier` mistakenly recognizes the widget outside of the `Navigator` to be its sibling
*  So we end up dropping the semantics node of the `TextField` rendered before it. 

The fix is to let `Navigator` generate a semantics node so that `ModalBarrier` doesn't mistakenly think widgets outside of `Navigator` are its siblings.  

`Navigator` doesn't currently do this, which causes all the nodes generated from its widget subtree to be directly attached to the parent semantics node above `Navigator` - since this is also the parent of `TextField`, it considers them siblings. 

Fixes https://github.com/flutter/flutter/issues/129324

Remove more `textScaleFactor` references from flutter/flutter.  

- Some changes are related to label scaling: the padding EdgeInsets values of some chip subclasses scale linearly between predetermined "max" padding values and "min" padding values. Before they scale with the `textScaleFactor` scalar, now they scale with the font size and are still capped at the original "max" and "min" values.
- The rest of them are tests or size heuristics that depend on `textScaleFactor`, these are replaced by an effective text scale factor computed using a default font size (which is determined in a pretty random fashion, but it will only make a difference on Android 14+).

No API changes in this batch. There are still some references left that I intend to remove in a different batch that would introduce API changes.

Fixes https://github.com/flutter/flutter/issues/141644

Fair amount of typos spotted and fixed. Some of them are in comments, some of them are in code and some of them are in nondart files.

There is no need for issues since it's a typo fix.

I have doubts about [packages/flutter_tools/lib/src/ios/core_devices.dart](https://github.com/flutter/flutter/compare/master...anisalibegic:flutter:master#diff-fdbc1496b4bbe7e2b445a567fd385677af861c0093774e3d8cc460fdd5b794fa), I have a feeling it might broke some things on the other end, even though it's a typo.

This PR introduces a new property `exitDuration` to Tooltip, the counterpart to `waitDuration`. The need for this is shown by #136586. This changes the behaviour of `showDuration` on mouse pointer devices. This is because the use cases for the current behaviour on touch screen devices vs mouse pointer devices is fundamentally different.

<details>
<summary>Demo: tooltip with showDuration set</summary>

Tooltip disappears after 100 ms when moving away the mouse. Tooltip will not disappear when hovered.

https://github.com/flutter/flutter/assets/5138348/81d36dc9-78e0-4723-a84b-2552843ee181

</details>

Currently, when `showDuration` is set, this adjusts the time it takes for the tooltip to hide _after_ a mouse pointer has left the tooltip. This is not the same use case as its effect on touch screen devices, where it dictates how long the tooltip stays on screen after a long press. That is needed because the tooltip takes up screen space and there is not an intuitive way to hide it, whereas when using a mouse users expect to simply have to hover somewhere else. Having the tooltip stay around will look broken.

Thus, this PR splits the two use cases. `showDuration` no longer affects mouse pointer devices at all*. There is a precedent for such mouse pointer-only behaviour in `waitDuration`. Instead, I have split up the two use cases and created the new property `exitDuration`, which will still allow for tweaking the time it takes for the tooltip to hide after the user has moved their mouse pointer somewhere else.

*Note: Should `showDuration` affect [this line](https://github.com/flutter/flutter/blob/e33d4b86270e3c012ba13d68d6e90f2eabc4912b/packages/flutter/lib/src/material/tooltip.dart#L610)?

Fixes #136586.

Note: I noticed that when I made the change, no tests were broken. Hopefully, the tests added here help that in the future. I also noticed that in the _existing_ tests, the `waitDuration` tests contain assertions that implicate that it is the role of `waitDuration` to change this behaviour, but that's not currently (nor in the new behaviour) true, so I have fixed those tests.

Updated unit tests for `Tooltip` to have M2 and M3 versions.

More info in #139076

issue: https://github.com/flutter/flutter/issues/137438

Use case: I want to add action button is tooltip and thus want to disable tap to dismiss a tooltip.

![image](https://github.com/flutter/flutter/assets/108393416/39c606fd-d301-4ed4-a411-4916823e5757)

`OverlayPortal.overlayChild` contributes semantics to `OverlayPortal` instead of `Overlay` (#134921)

Fixes https://github.com/flutter/flutter/issues/134456

Fix flakiness: finalize dropped gestures in tests to release resources, and update doc-comment. (#136136)

Reverts flutter/flutter#131998

Reverting for https://github.com/flutter/flutter/issues/132222

Fixes https://github.com/flutter/flutter/issues/59413

This relocates `mock_canvas.dart` and `recording_canvas.dart` from `flutter/test/rendering` to `flutter_test`. 

The testing functionality afforded by mock_canvas should be available to everyone, not just the framework. :)

mock_canvas.dart needed a bit of cleanup - things like formatting and super parameters.

Fixes https://github.com/flutter/flutter/issues/129969 by making tooltip text unselectable (for now). 
Also fixes some other issues uncovered when I was writing the tests.

Currently `getTransformTo` only works on ancestors. I'll try to add a new method that computes the transform from 2 arbitrary render objects in the same render tree in a follow-up PR and make `Selectable` use that method instead.

Fixes https://github.com/flutter/flutter/issues/129025

Also 
- simplifies OverlayPortal code a bit and adds an assert.
-  `Tooltip` shouldn't rebuild when hiding/showing the tooltip

It's time to say good bye to an old friend. 
It has outlived its usefulness.
Farewell, AbstractNode! 🫡

Updates most of the unit tests in the packages/flutter/test/material folder so that they'll pass if ThemeData.useMaterial3 defaults to true.

All of the tests have wired useMaterial3 to false and will need to be updated with a M3 version.

related to #127064

https://github.com/flutter/flutter/issues/7151 isn't a problem with OverlayPortal so the test is removed.
Also removed some `mounted` checks since they're no longer needed.

Fixes https://github.com/flutter/flutter/issues/127575

The `_handleMouseEnter` and `_handleMouseExit` calls are balanced, but the tooltip could be dismissed by an external `PointerDown` event interacting with a different UI component so the ` assert(_activeHoveringPointerDevices.isNotEmpty);` does not really make sense.

Fixes https://github.com/flutter/flutter/issues/117627

### Behavior changes:
1. If fade in/fade out animation is already in progress, hiding/showing the tooltip will immediately take effect without waiting for `waitDuration`.
2. A PointerDownEvent that doesn't become a part of a "trigger" gesture dismisses the tooltip, even for hovered ones.
3. The OverlayEntry is now updated only when the previous tooltip was completely dismissed. This can be fixed by OverlayPortal but I'm not sure what the correct behavior is.

Fixing #126206 and #113388 issues

*The IgnorePointer is preventing the richMessage touch events being recognized. Just removing that from*

*Solves #126206 and #113388*

* Make Flex,Row,Column const for real

* dart fix --apply

* fix snippets

* fix integration test

* add comment

This reverts commit d2788080.

* Deprecate MediaQuery[Data].fromWindow

* ++

* dart fix

* Check whether slider is mounted before interaction, no-op if unmounted (#113556)

* Check whether slider is unmounted before interaction

* Update slider.dart

* Update Slider

* Add test

* Update slider_test.dart

* Update packages/flutter/test/material/slider_test.dart
Co-authored-by: Taha Tesser <tessertaha@gmail.com>
Co-authored-by: Taha Tesser <tessertaha@gmail.com>

* exposed tooltip longPress action when available

* updated tooltip test

* updated date picker test

---------
Co-authored-by: Mingyu <lyming90@gmail.com>
Co-authored-by: Taha Tesser <tessertaha@gmail.com>
Co-authored-by: Harper Liu <harperl0818@gmail.com>

* Revert "Exposed tooltip longPress action when available (#117338)"

This reverts commit 38e3930f.

* Revert "fixes android_semantics_integration_test to expect long press for tootip"

* Enable  lint

* note about discarded_futures

* note about use_decorated_box

* update note on require_trailing_commas

* Exposed tooltip longPress action when available (Trigger mode is long press)