Auto merge of #28253 - ghostd:gh-25756, r=jdm

Add PRECONDITION_FAILED to grouping_formatter.py

<!-- Please describe your changes on the following line: -->
Port some code as described in #25756

---
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- [ ] `./mach build -d` does not report any errors
- [ ] `./mach test-tidy` does not report any errors
- [ ] These changes fix #25756 (GitHub issue number if applicable)

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- [ ] There are tests for these changes OR
- [ ] These changes do not require tests because ___

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tests/wpt/grouping_formatter.py

@@ -47,6 +47,7 @@ class ServoFormatter(base.BaseFormatter):
             'TIMEOUT': 0,
             'SKIP': 0,
             'CRASH': 0,
+            'PRECONDITION_FAILED': 0,
         }
 
         self.unexpected_tests = {
@@ -56,6 +57,7 @@ class ServoFormatter(base.BaseFormatter):
             'ERROR': [],
             'TIMEOUT': [],
             'CRASH': [],
+            'PRECONDITION_FAILED': [],
         }
 
     def get_move_up_and_clear_eol_codes(self):
@@ -264,6 +266,7 @@ class ServoFormatter(base.BaseFormatter):
         output += text_for_unexpected_list(u"crashed unexpectedly", 'CRASH')
         output += text_for_unexpected_list(u"had errors unexpectedly", 'ERROR')
         output += text_for_unexpected_list(u"failed unexpectedly", 'FAIL')
+        output += text_for_unexpected_list(u"precondition failed unexpectedly", 'PRECONDITION_FAILED')
         output += text_for_unexpected_list(u"timed out unexpectedly", 'TIMEOUT')
         output += text_for_unexpected_list(u"passed unexpectedly", 'PASS')
         output += text_for_unexpected_list(u"unexpectedly okay", 'OK')