The spec requires \x in strings to be followed by two hex digits; Chrome appears to enforce this, so conforming with the spec here should be pretty safe.
Created attachment 128682 [details]
Attachment 128682 [details] did not pass style-queue:
Failed to run "['Tools/Scripts/check-webkit-style', '--diff-files', u'LayoutTests/ChangeLog', u'LayoutTests/fast..." exit_code: 1
Total errors found: 2 in 12 files
If any of these errors are false positives, please file a bug against check-webkit-style.
Fixed in r108841