In update-test-expectation, skip lines with directories.

third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/update_test_expectations.py

Index: third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/update_test_expectations.py
diff --git a/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/update_test_expectations.py b/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/update_test_expectations.py
index 5d60a28a4514760b4b3eb1bfec171f3d125706fa..132b8bd1627dff7c43ad038bea79f3c7c335276d 100644
--- a/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/update_test_expectations.py
+++ b/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/update_test_expectations.py
@@ -104,6 +104,11 @@ class RemoveFlakesOMatic(object):
         if not self._has_pass_expectation(expectations):
             return False
 
+        # Don't check lines that have expectations for directories, since
+        # the flakiness of all sub-tests isn't as easy to check.
+        if self._is_directory(test_expectation_line.path):
+            return False
+
         # The line can be deleted if the only expectation on the line that appears in the actual
         # results is the PASS expectation.
         builders_checked = []
@@ -191,6 +196,12 @@ class RemoveFlakesOMatic(object):
                                      'SKIP')
         return any(s in expectations for s in unstrippable_expectations)
 
+    def _is_directory(self, path):
+        """Checks whether a path relative to the layout tests directory is a directory."""
+        filesystem = self._host.filesystem
+        abs_path = filesystem.join(self._port.layout_tests_dir(), path)
+        return filesystem.isdir(abs_path)
+
     def _get_builder_results_by_path(self):
         """Returns a dictionary of results for each builder.