Description

iOS logging broke with #54132. The migration missed this logic:

    // The VM service will not publish logging events unless the debug stream is being listened to.
    // onDebugEvent listens to this stream as a side effect.
    unawaited(connectedVmService.onDebugEvent);

If the debug stream isn't listened to, the VM service won't pass along Stdout/Stderr events.

flutter attach now shows logs.

Related Issues

Fixes #65519.

Tests

Updated ios_device_logger_test.

Checklist

• I read the [Contributor Guide] and followed the process outlined there for submitting PRs.
• I signed the [CLA].
• I read and followed the [Flutter Style Guide], including [Features we expect every widget to implement].
• I read the [Tree Hygiene] wiki page, which explains my responsibilities.
• I updated/added relevant documentation (doc comments with ///).
• All existing and new tests are passing.
• The analyzer (flutter analyze --flutter-repo) does not report any problems on my PR.
• I am willing to follow-up on review comments in a timely manner.

Breaking Change

• No, no existing tests failed, so this is not a breaking change.
• Yes, this is a breaking change. If not, delete the remainder of this section.