Add flag-specific baseline search path to run-webkit-tests.

third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/base.py

Index: third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/base.py
diff --git a/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/base.py b/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/base.py
index 3e8db9d90f69b74d93410489e056138b57390bc8..165e1d0f44e86b1858240365dd5646a10852a114 100644
--- a/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/base.py
+++ b/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/base.py
@@ -300,7 +300,10 @@ class Port(object):
         return [self._filesystem.join(path, suite.name) for path in self.default_baseline_search_path()]
 
     def baseline_search_path(self):
-        return self.get_option('additional_platform_directory', []) + self._compare_baseline() + self.default_baseline_search_path()
+        return (self.get_option('additional_platform_directory', []) +
+                self._flag_specific_baseline_search_path() +
+                self._compare_baseline() +
+                self.default_baseline_search_path())
 
     def default_baseline_search_path(self):
         """Return a list of absolute paths to directories to search under for
@@ -1265,6 +1268,11 @@ class Port(object):
         return [self._filesystem.join(self.layout_tests_dir(), 'FlagExpectations', flag.lstrip('-'))
                 for flag in self.get_option('additional_driver_flag', [])]
 
+    def _flag_specific_baseline_search_path(self):
+        # TODO(skobes): Baselines specific to both flag and platform?
+        return [self._filesystem.join(self.layout_tests_dir(), 'flag-specific', flag.lstrip('-'))
+                for flag in self.get_option('additional_driver_flag', [])]
+
     def expectations_dict(self):
         """Returns an OrderedDict of name -> expectations strings.
         The names are expected to be (but not required to be) paths in the filesystem.