Add a way to mark a test as missing expectations. We avoided added this...

webkit/tools/layout_tests/layout_package/compare_failures.py

Index: webkit/tools/layout_tests/layout_package/compare_failures.py
===================================================================
--- webkit/tools/layout_tests/layout_package/compare_failures.py	(revision 30861)
+++ webkit/tools/layout_tests/layout_package/compare_failures.py	(working copy)
@@ -118,7 +118,8 @@
                       'CRASH')
     PrintFilesFromSet(self._missing,
                       "Missing expected results",
-                      output)
+                      output,
+                      'MISSING')
 
   def _CalculateRegressions(self):
     """Calculate regressions from this run through the layout tests."""
@@ -156,7 +157,9 @@
       # expected files.
       elif (is_missing and
             not self._expectations.IsRebaselining(test) and
-            not self._expectations.IsIgnored(test)):
+            not self._expectations.IsIgnored(test) and
+            (test_expectations.MISSING not in
+             self._expectations.GetExpectations(test))):
         missing.add(test)
       elif is_image_failure and is_text_failure:
         if (not test_expectations.FAIL in expectations and