This change affects Android and iOS devices using the TextField's context menu. After this change the context menu will fade out when scrolling the text and fade in when the scroll ends. 

If the scroll ends and the selection is outside of the view, then the toolbar will be scheduled to show in a future scroll end. This toolbar scheduling can be invalidated if the `TextEditingValue` changed anytime between the scheduling and when the toolbar is ready to be shown.

This change also fixes a regression where the TextField context menu would not fade when the selection handles where not visible.

When using the native browser context menu this behavior is not controlled by Flutter.

https://github.com/flutter/flutter/assets/948037/3f46bcbb-ba6f-456c-8473-e42919b9d572

Fixes #52425
Fixes #105804
Fixes #52426

This change uses `CapturedTheme`s to capture the themes from the context the selection handles were built in and wraps the handles with them so they can correctly inherit `Theme`s from local `Theme` widgets.

`CapturedTheme`s only captures `InheritedTheme`s, so this change also makes `_InheritedCupertinoTheme` an `InheritedTheme`. This is so we can capture themes declared under a `CupertinoTheme`, for example `primaryColor` is used as the selection handle color.

Fixes #74890

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

I continued [my mission](https://github.com/flutter/flutter/pull/141431) to find as many typos as I could. This time it's a smaller set than before.

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

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.

Contributes to https://github.com/flutter/devtools/issues/6909.

This PR changes the regular cursor to a floating cursor when a long press occurs.

This is a new feature. Fixes  #89228

Re-enables skipped flaky test now that the underlying cause of flakiness (GPU memory leak) has been fixed in the engine and the fix has rolled into the framework.

The fix is here: https://github.com/flutter/engine/pull/49336

Fixes https://github.com/flutter/flutter/issues/137669

Reverts flutter/flutter#140462
Initiated by: cbracken
This change reverts the following previous change:
Original Description:
The test was flaky before due to overflowing GPU memory during the test. The memory leak was fixed here https://github.com/flutter/engine/pull/49214

Fixes https://github.com/flutter/flutter/issues/137669

As a side effect of the fix, this test also runs much faster, from about 3 minutes on my Macbook down to about 25 seconds.

The test was flaky before due to overflowing GPU memory during the test.
The memory leak was fixed here
https://github.com/flutter/engine/pull/49214

Fixes https://github.com/flutter/flutter/issues/137669

As a side effect of the fix, this test also runs much faster, from about
3 minutes on my Macbook down to about 25 seconds.

## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-new channel
on [Discord].

<!-- Links -->
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Fixes #123107

Adds a customizable semantic label so that the clear button on the Cupertino text field will be picked up by screen readers.

https://github.com/flutter/flutter/assets/58190796/de31d9dd-923c-402f-a55b-e5cc77ea68bb

## Description

This starts the deprecation of the `RawKeyEvent`/`RawKeyboard` event system that has been replaced by the `KeyEvent`/`HardwareKeyboard` event system.

Migration guide is available here: https://docs.flutter.dev/release/breaking-changes/key-event-migration

## Related Issues
 - https://github.com/flutter/flutter/issues/136419

## Related PRs
 - https://github.com/flutter/website/pull/9889

## Description

This PR adds the 'Share' button to the text selection toolbar on Android.

## Related Issue

Fixes https://github.com/flutter/flutter/issues/138728

## Tests

Refactor a lot of existing tests in order to:
- make them more readable (avoid duplication by introducing helper functions, specify explictly check which buttons are expected).
- make them more accurate (check that expected buttons are visible instead of just checking the number of buttons).

For instance, previous tests contained sections such as:

```dart

      // Collapsed toolbar shows 3 buttons.
      expect(
        find.byType(CupertinoButton),
        isContextMenuProvidedByPlatform ? findsNothing : isTargetPlatformIOS ? findsNWidgets(6) : findsNWidgets(3)
      );

```

Where the comment is obsolete, the two cases (6 widgets and 3 widgets) are not explicit (which buttons are expected?), and not accurate (will pass if the number of buttons is right but the buttons are the wrong ones).

Skipping the test due to
https://github.com/flutter/flutter/issues/137669. It's not clear which
PR started it, so we can't revert anything, and the fix is not yet clear
either. However, the flakiness is very high and is disruptive to the
Flutter team.

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

Hopefully this fixes https://github.com/flutter/flutter/issues/110076 by removing the `Path.combine` call. Not sure how I can verify in a test that `Path.combine` is not called.

Fixes https://github.com/flutter/flutter/issues/133241
and some CupertinoTextField cleanup.

In native iOS, users are able to select text and initiate a share menu, which provides several standard services, such as copy, sharing to social media, direct ability to send to various contacts through messaging apps, etc. 

https://github.com/flutter/engine/assets/36148254/d0af7034-31fd-412e-8636-a06bbff54765

This PR is the framework portion of the changes that will allow Share to be implemented.
The corresponding merged engine PR is [here](https://github.com/flutter/engine/pull/44554)
This PR addresses https://github.com/flutter/flutter/issues/107578
More details are available in this [design doc](https://github.com/flutter/engine/pull/flutter.dev/go/add-missing-features-to-selection-controls)

This PR makes sure we do not select beyond the text boundary at the tapped position unless, we tap at the end of the text which in that case we should select the previous text boundary.

```dart
    // if x is a boundary defined by `textBoundary`, most textBoundaries (except
    // LineBreaker) guarantees `x == textBoundary.getLeadingTextBoundaryAt(x)`.
    // Use x - 1 here to make sure we don't get stuck at the fixed point x.
    final int start = textBoundary.getLeadingTextBoundaryAt(extent.offset - 1) ?? 0;
```

This was originally carried over from https://github.com/flutter/flutter/blob/f468f3366c26a5092eb964a230ce7892fda8f2f8/packages/flutter/lib/src/widgets/editable_text.dart#L4167-L4179 which used this `x - 1` to be able to move to the previous word boundary when navigating with a keyboard. When selecting by tapping/clicking we do not want to move past the text boundary at the tapped position so this adjustment is not needed.

Fixes #132126

This PR adds framework support for the Search Web feature in iOS. 

https://github.com/flutter/flutter/assets/36148254/c159f0d9-8f14-45e7-b295-e065b0826fab

The corresponding merged engine PR can be found [here](https://github.com/flutter/engine/pull/43324).
This PR addresses https://github.com/flutter/flutter/issues/82907 
More details are available in this [design doc](https://docs.google.com/document/d/1QizXwBiO-2REIcEovl5pK06BaLPOWYmNwOE5jactJZA/edit?resourcekey=0-1pb9mJiAq29Gesmt25GAug)

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.

This PR adds framework support for the Look Up feature in iOS. 

https://github.com/flutter/flutter/assets/36148254/d301df79-4e23-454f-8742-2f8e39c2960c

The corresponding merged engine PR can be found [here](https://github.com/flutter/engine/pull/43308).
This PR addresses https://github.com/flutter/flutter/issues/82907 
More details are available in this [design doc.](flutter.dev/go/add-missing-features-to-selection-controls)

This is the same PR as https://github.com/flutter/flutter/pull/130532, this is an attempt to fix the Google Testing issue

iOS OCR keyboard input support.

CupertinoTextSelectionToolbar is different from the native one, with some UI and UX issues. More details on the linked issue.

https://github.com/flutter/flutter/issues/127756

Currently the only problem that I listed on the linked issue that I couldn't fix was the horizontal scrolling, but to workaround this I added a GestureDetector to change pages when swiping the toolbar. It's not exactly the same as native as there is no scroll animation, but it works.

I'm creating this PR a little early to have some feedback as these changes were more complex than the ones in my last PR. Probably best if @justinmc is involved 😅

|Version|Video|
|-|-|
|Flutter Old|<video src="https://github.com/flutter/flutter/assets/12024080/7cf81075-46ec-4970-b118-cc27b60ddac0"></video>|
|Flutter New|<video src="https://github.com/flutter/flutter/assets/12024080/c9e27a53-f94c-4cb0-9b76-e47b73841dcb"></video>|
|Native|<video src="https://github.com/flutter/flutter/assets/12024080/468c7d5b-ba93-4bd4-8f6e-8ec2644b9866"></video>|

Desktop text selection toolbar no longer flashes before closing.

Before this change on a quick touch drag the cursor, where the touch is not on the previous collapsed selection, the cursor would move to the tapped position.

After this change on a quick touch drag the cursor does not move unless the touch is on the previously collapsed selection. This is inline with native behavior.

Before|After|Native
--|--|--
<video src="https://user-images.githubusercontent.com/948037/233224775-f33b42b5-5638-416c-9278-39ecd964e3bb.mov" />|<video src="https://user-images.githubusercontent.com/948037/233224760-2d1af657-8d99-45fc-8499-9567f17d533e.mov" />|<video src="https://user-images.githubusercontent.com/948037/233224790-f5997cfa-7370-4891-8952-11ef8057a729.mov" />

fixes https://github.com/flutter/flutter/issues/99360

iOS now hides the selection handles and shows red selection when tapping a misspelled word, like native.

#125151 introduced the magnifier on touch drag gestures, but when showing the magnifier the toolbar is implicitly hidden, this change makes the toolbar re-appear on drag end for double tap + drag.

This change shows the magnifier on touch drag gestures for Android and iOS and hides it when the drag ends.

Fixes #118268

Fixes IgnorePointer and AbsorbPointer to only block user interactions…

TapAndDragGestureRecognizer should declare victory immediately when drag is detected

Match iOS Longpress behavior with native