* remove json_schema dep

* remove unnecessary pin

* removed unused dep

* remove unused impport

* Fix incorrect condition

* Add outer try block for obtainKey errors. Add docs.

* change to // from ///, and do specific error handling

* Add return statement after error

* Add test

flutter/engine@6d7eb5218 Revert "Android embedding refactor pr3 add remaining systemchannels (flutter/engine#7874)" (flutter/engine#7886)
flutter/engine@dad6ec01c Correct onAccessibilityFeaturesChanged docs (flutter/engine#7883)
flutter/engine@fc1a68ea1 Roll src/third_party/skia e0a6a048bc4a..7738736f9622 (4 commits) (flutter/engine#7884)
flutter/engine@a150cc125 Fix minor typos in accessibility action docs (flutter/engine#7882)
flutter/engine@bf1654450 Roll src/third_party/skia 249a25730521..e0a6a048bc4a (2 commits) (flutter/engine#7881)
flutter/engine@d60ef0c36 Roll src/third_party/skia ce62dec02293..249a25730521 (15 commits) (flutter/engine#7879)
flutter/engine@1263d28ab Fix caret being at left edge when newline pressed on centered text (flutter/engine#7875)

* Roll engine to f45572e95f93edb89b6750a4f36ad8ed7c0a2560

* update goldens

* update goldens version

https://github.com/flutter/engine/compare/163a2fd5e140...f37b09a11b28

git log 163a2fd5e140d10a30645e73031054ef39105d87..f37b09a11b281b2a4e5dfcb45029069c3ac6e460 --no-merges --oneline
f37b09a11 [fuchsia][SCN-1054] Map elevation onto -Z in Scenic (flutter/engine#7834)

The AutoRoll server is located here: https://autoroll.skia.org/r/flutter-engine-flutter-autoroll

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If the roll is causing failures, please contact the current sheriff (liyuqian@google.com), and stop
the roller if necessary.

https://github.com/flutter/engine/compare/033f2072c315...163a2fd5e140

git log 033f2072c315d48b4d7680d4cbbe856012b1259b..163a2fd5e140d10a30645e73031054ef39105d87 --no-merges --oneline
163a2fd5e Revert "Android embedding refactor pr3 add remaining systemchannels (#7738)" (flutter/engine#7849)
0d6ff1669 Shut down and restart the Dart VM as needed. (flutter/engine#7832)
256db4bc2 Android embedding refactor pr3 add remaining systemchannels (flutter/engine#7738)
02d7ca31d Don't call static method from instance variable (flutter/engine#7841)
10cee612b Delete GL textures when they are released from the texture registry. (flutter/engine#7836)
69e460607 Fix NullPointerException in SurfaceTextureRegistryEntry (flutter/engine#7837)
9a965bc3d Fix NullPointerException in ResourceCleaner (flutter/engine#7838)
2acd79480 Add fml::FileExists implementation for Windows (flutter/engine#7845)
fa38a985c Update buildroot to 7f64ff4928e to unblock Mac builds. (flutter/engine#7846)
1ba329550 Add support for calling into other plugins from a background context on iOS (flutter/engine#7843)
df2fc973a Roll src/third_party/skia 154acd7a1374..be9aff25bddc (13 commits) (flutter/engine#7842)
0ca1d1f31 Remove the Dart JIT snapshot data from AOT builds of the embedder library (flutter/engine#7806)
c51ea4157 Roll src/third_party/skia 7a74c7cb6da0..154acd7a1374 (1 commits) (flutter/engine#7840)
ecbaea10a Ensure to pass dill file after VM options for gen_snapshot (flutter/engine#7839)
5d3f7145a Roll src/third_party/skia b00f7b34751b..7a74c7cb6da0 (1 commits) (flutter/engine#7835)
733739938 Roll src/third_party/skia 9a88bee122f1..b00f7b34751b (24 commits) (flutter/engine#7831)
6f318efe0 Move up ndk version that is being downloaded(old one no longer available) (flutter/engine#7830)
a8aa1ee06 Track flow id (flutter/engine#7826)
b1ce6b72f Roll src/third_party/skia a0dcd29f536b..9a88bee122f1 (4 commits) (flutter/engine#7825)
dbc166387 Roll src/third_party/skia 6152470dc69e..a0dcd29f536b (2 commits) (flutter/engine#7824)
942677695 Roll src/third_party/skia 4037f7f5d8b4..6152470dc69e (1 commits) (flutter/engine#7823)
e2394ad77 Add flow events connecting pointer events to frames (flutter/engine#7807)
0a5a7c56d Roll src/third_party/skia 09c01e9df260..4037f7f5d8b4 (3 commits) (flutter/engine#7821)
b867f4858 Roll src/third_party/skia 186669c4128b..09c01e9df260 (5 commits) (flutter/engine#7820)
af39e22c3 Fix tests that were committed after cirrus ran (flutter/engine#7819)
1f2cbf792 Roll src/third_party/dart 0a7dcf17eb..c92d5ca288 (64 commits)

The AutoRoll server is located here: https://autoroll.skia.org/r/flutter-engine-flutter-autoroll

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+/master/autoroll/README.md

If the roll is causing failures, please contact the current sheriff (liyuqian@google.com), and stop
the roller if necessary.

Revert "Add support for binary compression of dynamic patches by the flutter tool. (#27754)" (#28031)

This reverts commit b47da6c2.

* Discover port over mDNS 

* Update BUILD.gn for tools

Because we now have 2 separate GPU and UI threads.

* Refactor for iOS.

* For android_xxx_unopt_arm64&ios_xxx_unopt_arm, remove the _arm64/_arm suffix.
dart generated in host_xxx_unopt/host_xxx has an arch of x86_64 which supports arm64/arm.

* Remove suffixes for various archs.

Disable prefer_collection_literals in the analyzer until we can update to using set literals (#28024)

* Fixes Cupertino switch vibration

* Added sample code for a simple Icon, ref: #21136

* Removed duplicate line.

* Fixed incoreect parameter.

* Update icon.dart

Removed empty prose and added better context for sample code. Changed sample code for better visibility in execution of default app themes.

* Alas, Trailing space.

Nixed trailing space in comments.

Fixes https://github.com/flutter/flutter/issues/25025

Re-applies #27409 by reverting #27919

The analyzer issue (dart-lang/sdk#35940) has been temporarily
worked around by virtue of #27929

This fixes the offline Dash/Zeal docs generation to use the newly added dartdoc markers for different entity types to make it more exact when finding entity names.

Bumped Dartdoc to the next release.

This is a partial re-application of #24669

https://github.com/flutter/flutter/issues/24413

This converts all remaining "## Sample code" segments into snippets, and fixes
the snippet generator to handle multiple snippets in the same dartdoc block
properly.

I also generated, compiled, and ran each of the existing application samples,
and fixed them up to be more useful and/or just run without errors.

This PR fixes these problems with examples:

1. Switching tabs in a snippet now works if there is more than one snippet in
   a single dartdoc block.
2. Generation of snippet code now works if there is more than one snippet.
3. Contrast of text and links in the code sample block has been improved to
   recommended levels.
4. Added five new snippet templates, including a "freeform" template to make
   it possible to show examples that need to change the app instantiation.
5. Fixed several examples to run properly, a couple by adding the "Scaffold"
   widget to the template, a couple by just fixing their code.
6. Fixed visual look of some of the samples when they run by placing many
   samples inside of a Scaffold.
7. In order to make it easier to run locally, changed the sample analyzer to
   remove the contents of the supplied temp directory before running, since
   having files that hang around is problematic (only a problem when running
   locally with the `--temp` argument).
8. Added a `SampleCheckerException` class, and handle sample checking
   exceptions more gracefully.
9. Deprecated the old "## Sample code" designation, and added enforcement for
   the deprecation.
10. Removed unnecessary `new` from templates (although they never appeared in
   the samples thanks to dartfmt, but still).

Fixes #26398
Fixes #27411

This makes the code more consistent but also fixes our flutter-analyze bot.

Issue https://github.com/dart-lang/sdk/issues/35940

This reverts commit 46cabdab.

https://github.com/flutter/engine/compare/d48de7a3ec97...3757390fa4b0

git log d48de7a3ec97ebf7ffe543aa74993efa51064789..3757390fa4b00d2d261bfdf5182d2e87c9113ff9 --no-merges --oneline
3757390fa Roll src/third_party/dart ecd7a88606..0a7dcf17eb (4 commits)
61d3080d5 Add FFI to libraries.yaml. (flutter/engine#7811)
f5259b8e2 Roll src/third_party/skia b6f53783337e..186669c4128b (8 commits) (flutter/engine#7816)
816921b9e Use newer Skia API for PathMeasure (flutter/engine#7809)
da56ff9c6 Roll src/third_party/skia 94a5328e0e4b..b6f53783337e (8 commits) (flutter/engine#7812)
04fbc2545 Roll src/third_party/skia 66f09a72995a..94a5328e0e4b (1 commits) (flutter/engine#7810)
347d690b2 Add support for new Scenic clip planes. (flutter/engine#7804)
309b90ca5 Roll src/third_party/skia 14d64dd4c47c..66f09a72995a (8 commits) (flutter/engine#7805)
1dead52a8 Roll src/third_party/skia 0b6ae6386d34..14d64dd4c47c (10 commits) (flutter/engine#7802)
74d94e52c Revert "Use all font managers to discover fonts for strut. (#7734)" (flutter/engine#7801)
769016c88 Roll src/third_party/skia 63d477cd99b0..0b6ae6386d34 (9 commits) (flutter/engine#7798)
f7eb3cb20 Roll src/third_party/skia 217acf58d0d8..63d477cd99b0 (1 commits) (flutter/engine#7797)
c4a55552b Use all font managers to discover fonts for strut. (flutter/engine#7734)
17b7d1e0a Roll src/third_party/dart 754e5f404c..ecd7a88606 (8 commits)
b4ed8cff3 Roll src/third_party/skia 233fc0b03c02..217acf58d0d8 (1 commits) (flutter/engine#7795)
27ab9f7af Roll src/third_party/skia 454e5fb7457d..233fc0b03c02 (4 commits) (flutter/engine#7794)
c58f5fefe Roll src/third_party/dart fdfe40ea95..754e5f404c (13 commits)

The AutoRoll server is located here: https://autoroll.skia.org/r/flutter-engine-flutter-autoroll

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+/master/autoroll/README.md

If the roll is causing failures, please contact the current sheriff (liyuqian@google.com), and stop
the roller if necessary.

This reverts commit d8cd2ff4.

This reverts commit 1d93e924.