Workaround solution for: https://github.com/flutter/flutter/issues/121231
See https://github.com/flutter/flutter/issues/120808#issuecomment-1551826299 Error Case 2 for more information.

Sometimes the `ios-deploy` process does not return the logs from the application. We've been unable to figure out why. This is a solution to workaround that by using `idevicesyslog` alongside `ios-deploy` as a backup in getting the log for the Dart VM url. As explained in https://github.com/flutter/flutter/issues/120808#issuecomment-1551826299, when error case 2 happens, the `idevicesyslog` does successfully find the Dart VM.

Also, in the comments of the code it mentions `syslog` is not written on iOS 13+, this was added in response to this issue: https://github.com/flutter/flutter/issues/41133.

However, `idevicesyslog` does in fact work (at least for iOS 16), we use it to collect device logs for our CI tests already: https://github.com/flutter/flutter/blob/1dc26f80f04c1c1091a83c5fead9b3aa83483292/dev/devicelab/lib/framework/devices.dart#L998-L1006

This allows us to check for performance differences in local Web SDKs.

## Pre-launch Checklist

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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].

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[Contributor Guide]:
https://github.com/flutter/flutter/wiki/Tree-hygiene#overview
[Tree Hygiene]: https://github.com/flutter/flutter/wiki/Tree-hygiene
[test-exempt]:
https://github.com/flutter/flutter/wiki/Tree-hygiene#tests
[Flutter Style Guide]:
https://github.com/flutter/flutter/wiki/Style-guide-for-Flutter-repo
[Features we expect every widget to implement]:
https://github.com/flutter/flutter/wiki/Style-guide-for-Flutter-repo#features-we-expect-every-widget-to-implement
[CLA]: https://cla.developers.google.com/
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[breaking change policy]:
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[Discord]: https://github.com/flutter/flutter/wiki/Chat

Take screenshot on devicelab failure

Revert "[Impeller] Temporary flag flip for devicelab tests to use Impeller redux. (#122340)" (#122362)

Revert "[Impeller] Temporary flag flip for devicelab tests to use Impeller redux."

This reverts commit 21b8b729.

[Impeller] Temporary flag flip for devicelab tests to use Impeller.

Funnel devicelab tests through utils process methods

This reverts commit 275ab9c6.

Revert "Reland "Remove references to Observatory (#118577)""

This reverts commit 298d8c76.

This reverts commit 2df140f4.

Observatory is being deprecated for Dart 3.0 so it should no longer be
referenced in tooling messaging / flags.

See https://github.com/dart-lang/sdk/issues/50233

* Testing whether emulator is possible.

* Adding changes to see if emulator can be used from recipe.

* adding emulator support.

* Add the emulator flag for testing.

* Using string for boolean since it cannot be parsed in properties

* Checking to see if these changes are being used.

* Updated bool back to string

* Remove trailing whitespace from file.

Adds a test that invokes flutter run in release mode on macOS desktop,
waits for successful launch and the flutter command list, then sends the
'q' command to quit the running app.

This adds an integration test for https://github.com/flutter/flutter/pull/100504.

Issue: https://github.com/flutter/flutter/issues/100348 (fix)
Issue: https://github.com/flutter/flutter/issues/97978 (partial fix)
Issue: https://github.com/flutter/flutter/issues/97977 (partial fix)
Umbrella issue: https://github.com/flutter/flutter/issues/60113

This reverts commit 5fd259be.

(Attempt to reland #85993)

This reverts commit 2175e64e.

Migrate core devicelab framework to null safety.