This reverts commit f1cd47ef.

When Focus.unfocus is called, the caller usually just thinks about wanting to remove focus from the node, but really, unfocus is a request to automatically pass the focus to another (hopefully useful) node.

This PR removes the focusPrevious flag from unfocus, and replaces it with a disposition enum that indicates where the focus should go from here.

The other value of the UnfocusDisposition enum is UnfocusDisposition.scope.

UnfocusDisposition.previouslyFocusedChild is closest to what focusPrevious used to do: focus the nearest enclosing scope and use its focusedChild field to walk down the tree, finding the leaf focusedChild. This PR modifies it slightly so that it walks up to the nearest focusable enclosing scope before trying to focus the children. This change addresses #48903

A new mode: UnfocusDisposition.scope will focus the nearest focusable enclosing scope of this node without trying to use the FocusScopeNode.focusedChild value to descend to the leaf focused child. This is useful as a default for both text field finalization and for what happens when canRequestFocus is set to false. It allows the scope to stay focused so that nextFocus/previousFocus still work as expected, but removes the focus from primary focus.

In addition to those changes, unfocus called on a FocuScope that wasn't the primary focus used to unfocus the primary focus instead. I removed that behavior, since it was buggy: if the primary focus was inside of a child scope, and you called unfocus on the parent scope, then the child scope could have focused another of its children instead, leaving the scope that you called unfocus on with hasFocus returning true still. If you want to remove the focus from the primary focus instead of the scope, that's easy enough to do: just call primaryFocus.unfocus().

Fixes #48903

* Reland "Live image cache" (#51441)

This reverts commit 419a2853.

* Make evict safer

This reverts commit 69080e07.

* Fix expression evaluation test leaking flutter_tester processes.

Let flutter_tester process complete, wait for it completion, kill the test only if didn't complete on time.

* Type annotation

This implements VisualDensity changes for text fields*. By default, the layout of the text field does not change.

If the ThemeData.visualDensity is set to a value other than zero, then the density of the UI will increase or decrease. See the VisualDensity docs for more information.

(*In reality, the changes are on the InputDecorator class, not on the text field.)

I also fixed a problem that I think I found with _Decoration where it doesn't compare isDense or isCollapsed as part of its operator==.

* 05dd02368 Roll src/third_party/dart 73f6d15665a3..7aa824076c34 (11 commits) (flutter/engine#16780)

* 9f439d9ef Roll src/third_party/skia 19304d88c8be..6d927b63a311 (3 commits) (flutter/engine#16782)

* effd8a069 Roll src/third_party/skia 6d927b63a311..a6572f78d084 (3 commits) (flutter/engine#16783)

* af90e8b11 Manually add third_party/dart/pkg/stagehand to DEPS (flutter/engine#16785)

* ae999f090 Roll fuchsia/sdk/core/mac-amd64 from O6w2L... to 8gjOI... (flutter/engine#16787)

* d0897c321 Roll src/third_party/dart 7aa824076c34..2ce1df76309d (11 commits) (flutter/engine#16788)

* 7af8d3ee9 Roll src/third_party/skia a6572f78d084..c8d092a060ad (1 commits) (flutter/engine#16789)

* fb3dc8603 Roll src/third_party/dart 2ce1df76309d..85f6d51c3fd1 (6 commits) (flutter/engine#16792)

* 468b371ff Roll src/third_party/skia c8d092a060ad..7a6db4cbf48b (2 commits) (flutter/engine#16795)

* ff921cd60 fuchsia: remove use of replace_as_executable (flutter/engine#16690)

* d590e9841 Evict BitmapCanvas(s) from cache when canvas allocation fails (flutter/engine#16793)

* 52070e3df Fix handler unregistration in C++ channels  (flutter/engine#16794)

* 592b3ff21 Roll src/third_party/skia 7a6db4cbf48b..d8575452ebf3 (3 commits) (flutter/engine#16799)

* 9ac76ad5a [web] changing user limits for macos (flutter/engine#16797)

* 7685e080b [web] Guard the remaining calls to window.onPlatformMessage (flutter/engine#16791)

* 328654311 Roll src/third_party/skia d8575452ebf3..adc9bbb2aaca (2 commits) (flutter/engine#16801)

* 29cff9eb5 Roll fuchsia/sdk/core/mac-amd64 from 8gjOI... to 3B3a6... (flutter/engine#16803)

* fc3a15e7f Roll src/third_party/skia adc9bbb2aaca..7b96793ccc5b (3 commits) (flutter/engine#16804)

* f1a9dc1c9 Roll src/third_party/skia 7b96793ccc5b..f0a13d04c233 (1 commits) (flutter/engine#16805)

* ecabc1037 Roll src/third_party/dart 85f6d51c3fd1..418923733006 (30 commits) (flutter/engine#16813)

* 858185cd5 Roll src/third_party/skia 659cc1c90705..19304d88c8be (5 commits) (flutter/engine#16778)

* ecdfc91d1 Roll fuchsia/sdk/core/linux-amd64 from PGfiE... to QU3ft... (flutter/engine#16779)

This reverts commit 59cc3cdf.

This reverts commit 492fb638.

Reason for revert: Dart HHH infrastructure including Golem builders are using older images which have older curl which does not support these flags. Upgrading images takes long time - so in the interim we are forced to revert to avoid accumulating gap in coverage.

Retry downloading Dart SDK at least 3 times with a 5 seconds wait in between retries

* Revert "Live image cache (#51249)"

This reverts commit e2dcdb60.

* fix tests for other commit

Adds utility code for managing list of plugin projects within a solution file, updating them as the plugins change.

This is a prototype of an approach to solution-level portion of Windows plugin tooling; it may not be what the final plugin handling on Windows uses, but it makes things much better in the short term, and gives us a baseline to evaluate other possible solution management systems against.

Part of #32719

Remove deprecated DefaultFocusTraversal widget

Fixes #51010

The test package differentiates between passing and not passing this
argument. A previous version had a bug that treated passing `0`
identically to not passing the argument, and the flutter test runner
relied on this bug by always passing a value and using a default of `0`.

- Remove the argument defaults throughout to make it clear that `null`
  is a valid value and the default.
- Remove the argument defaulting on the argument parser.
- Update the wording of the usage for this argument, this will also be
  updated on the `package:test` side.

* 5b0cbbe50 Roll fuchsia/sdk/core/mac-amd64 from _jvYk... to WZgbp... (flutter/engine#16692)

* cbb0ff8fd Roll src/third_party/skia c5ff41f2976e..7dfb46e7f397 (20 commits) (flutter/engine#16691)

* ab454ea08 Roll src/third_party/dart 0f141be8bd52..7469b87b042a (9 commits) (flutter/engine#16693)

* 1b7378494 fix param (flutter/engine#16694)

* bdd2cf869 Roll src/third_party/skia 7dfb46e7f397..9baef3593c3c (3 commits) (flutter/engine#16696)

* 8f0bbfad3 Roll src/third_party/skia 9baef3593c3c..ed1ff23c2768 (5 commits) (flutter/engine#16699)

* f052d2e03 Roll fuchsia/sdk/core/linux-amd64 from VHyDa... to YPr0t... (flutter/engine#16701)

* 3fe33257b Roll src/third_party/dart 7469b87b042a..e187e42593e8 (11 commits) (flutter/engine#16702)

* f83092a95 Roll src/third_party/skia ed1ff23c2768..a5097354217b (1 commits) (flutter/engine#16703)

* 6b3d43963 Roll src/third_party/skia a5097354217b..2c2db2762809 (1 commits) (flutter/engine#16704)

* fdabcaddf Enable lazy-async-stacks by-default in all modes (flutter/engine#16556)

* 02aa865da Fix the newline on some keyboards (flutter/engine#16560)

* cde7d47cb Roll src/third_party/dart e187e42593e8..81d4cc6bc99a (3 commits) (flutter/engine#16705)

* 14a2b03db Roll fuchsia/sdk/core/mac-amd64 from WZgbp... to 78ZcV... (flutter/engine#16706)

* 7b0453e40 Roll src/third_party/skia 2c2db2762809..9d4e31d6cda5 (1 commits) (flutter/engine#16707)

* 5cef6d0a8 Roll fuchsia/sdk/core/linux-amd64 from YPr0t... to CZTpy... (flutter/engine#16708)

* 0ef67b5e7 opt out dart:ui from nnbd (flutter/engine#16473)

* bc4a27fc2 [shell tests] Integrate Vulkan with Shell Tests (flutter/engine#16621)

* 2fdba5267 Roll src/third_party/skia 9d4e31d6cda5..62076977a0b7 (11 commits) (flutter/engine#16710)

* 969cfc17a Roll src/third_party/skia 62076977a0b7..1d589a578ca4 (6 commits) (flutter/engine#16712)

* 8eb727ec3 Flush the SkCanvas when submitting a frame in ShellTestPlatformViewVulkan::OffscreenSurface (flutter/engine#16717)

* e44f99bbe Roll src/third_party/skia 1d589a578ca4..706851dc99d9 (2 commits) (flutter/engine#16714)

* 60b27fd54 Reland "Remove usage of Dart_AllocateWithNativeFields" (flutter/engine#16713)

* 7a50e4de9 Roll src/third_party/dart 81d4cc6bc99a..fd20c7b92bb8 (31 commits) (flutter/engine#16716)

* 4aaafe0d2 Roll src/third_party/skia 706851dc99d9..df283d01cabb (3 commits) (flutter/engine#16719)

* e18aba332 Refactor of ClaimDartHandle -> AssociateWithDartWrapper (flutter/engine#16720)

* 66742b6d3 Roll src/third_party/skia df283d01cabb..3ffa7af75301 (1 commits) (flutter/engine#16722)

* e0303b03c Roll src/third_party/dart fd20c7b92bb8..6ef9131d82c4 (7 commits) (flutter/engine#16723)

* 0bd69f9d5 Roll src/third_party/skia 3ffa7af75301..77521d9e06e8 (2 commits) (flutter/engine#16725)

* 3e692865f Roll fuchsia/sdk/core/mac-amd64 from 78ZcV... to iYYAH... (flutter/engine#16726)

* 704396b32 Roll fuchsia/sdk/core/linux-amd64 from CZTpy... to -u-iU... (flutter/engine#16727)

* 645d4e631 Roll src/third_party/dart 6ef9131d82c4..5829fc7829d5 (3 commits) (flutter/engine#16728)

* b73dfed39 Roll src/third_party/skia 77521d9e06e8..392846665c40 (1 commits) (flutter/engine#16729)

* 2724727b1 Roll src/third_party/skia 392846665c40..bf5cb0f539e7 (1 commits) (flutter/engine#16730)

* ab0dd1297 [web] Running safari tests on LUCI (flutter/engine#16715)

* e5091a8ca Enable Vulkan-related shell unittests on Fuchsia (flutter/engine#16718)

* 930a80ac8 Fix some compiler warnings in newer versions of Clang. (flutter/engine#16733)

* 941aee35b [web] add comment to skipped safari test (flutter/engine#16737)

* 136a057f2 [web] Rename LineMetrics.text to LineMetrics.displayText (flutter/engine#16734)

* afe7968e6 [web] Paragraph.longestLine doesn't need to check for `isSingleLine` anymore (flutter/engine#16736)

* c3f4c1a08 Migrate Path to AssociateWithDartWrapper (flutter/engine#16753)

* d0c2418df Add support for Increase Contrast on iOS (flutter/engine#15343)

* 6d2cbb2db Roll src/third_party/skia bf5cb0f539e7..46f5c5f08b61 (2 commits) (flutter/engine#16732)

* f758eb97c Roll fuchsia/sdk/core/linux-amd64 from -u-iU... to 3rB22... (flutter/engine#16752)

* a4a1f4f6b Roll fuchsia/sdk/core/mac-amd64 from iYYAH... to 5B5jq... (flutter/engine#16744)

* 8caf6d1d3 Roll src/third_party/skia 46f5c5f08b61..9e8f60534464 (29 commits) (flutter/engine#16754)

* 340f85559 Roll fuchsia/sdk/core/mac-amd64 from 5B5jq... to g1vJn... (flutter/engine#16755)

* 9a9abb78f Roll src/third_party/skia 9e8f60534464..d1c90e10f0ca (1 commits) (flutter/engine#16757)

* 2e12cdc90 Roll src/third_party/skia d1c90e10f0ca..998066127e0d (1 commits) (flutter/engine#16759)

* 566cfae1b Roll src/third_party/skia 998066127e0d..57bc977e124c (3 commits) (flutter/engine#16762)

* 73fdff1e2 Roll fuchsia/sdk/core/linux-amd64 from 3rB22... to PGfiE... (flutter/engine#16763)

* ecca1750d Roll fuchsia/sdk/core/mac-amd64 from g1vJn... to mcI8X... (flutter/engine#16764)

* 4d505170a Roll src/third_party/skia 57bc977e124c..cc5415a8ce36 (1 commits) (flutter/engine#16767)

* 237ddb1be Roll src/third_party/skia cc5415a8ce36..1cec4d5e3d92 (2 commits) (flutter/engine#16769)

* 8da64e067 Roll src/third_party/dart 5829fc7829d5..c75256299280 (43 commits) (flutter/engine#16770)

* 0d87160bd Roll src/third_party/skia 1cec4d5e3d92..7d252302268a (2 commits) (flutter/engine#16771)

* 1aef7a436 Delete FlutterAppDelegate_Internal.h (flutter/engine#16772)

* b87bb0a16 [web] Fix canvas leak when dpi changes. Evict from BitmapCanvas cache under… (flutter/engine#16721)

* e0e24f579 Roll src/third_party/skia 7d252302268a..03b8ab225fd7 (8 commits) (flutter/engine#16773)

* 38dc2ea67 [i18n] Deprecates fuchsia.timezone.Timezone (flutter/engine#16700)

* 92abb22c6 Reland "Lift restriction that embedders may not trample the render thread OpenGL context in composition callbacks." (flutter/engine#16711)

* 971122b31 [web] Reduce the usage of unnecessary lists in pointer binding (flutter/engine#16745)

* d67005945 [web] Respect maxLines when calculating boxes for a range (flutter/engine#16749)

* 5496bb48c Roll src/third_party/skia 03b8ab225fd7..659cc1c90705 (4 commits) (flutter/engine#16774)

* bad1fbe3c Roll src/third_party/dart c75256299280..73f6d15665a3 (9 commits) (flutter/engine#16776)

* d2e2cc9d4 Roll fuchsia/sdk/core/mac-amd64 from mcI8X... to O6w2L... (flutter/engine#16777)

* 888a62cf2 Revert "Enable lazy-async-stacks by-default in all modes (#16556)" (flutter/engine#16781)