[test] Enable test status filtering by variant

tools/testrunner/local/utils.py

Index: tools/testrunner/local/utils.py
diff --git a/tools/testrunner/local/utils.py b/tools/testrunner/local/utils.py
index c880dfc34ebd83dc465efe5d9166559e442e8566..3e79e44afa22bff5fb623d1cb5451b5d9cf04b81 100644
--- a/tools/testrunner/local/utils.py
+++ b/tools/testrunner/local/utils.py
@@ -136,3 +136,24 @@ def URLRetrieve(source, destination):
       pass
   with open(destination, 'w') as f:
     f.write(urllib2.urlopen(source).read())
+
+
+class FrozenDict(dict):
+  def __setitem__(self, *args, **kwargs):
+    raise Exception('Tried to mutate a frozen dict')
+
+  def update(self, *args, **kwargs):
+    raise Exception('Tried to mutate a frozen dict')
+
+
+def Freeze(obj):
+  if isinstance(obj, dict):
+    return FrozenDict((k, Freeze(v)) for k, v in obj.iteritems())
+  elif isinstance(obj, set):
+    return frozenset(obj)
+  elif isinstance(obj, list):
+    return tuple(Freeze(item) for item in obj)
+  else:
+    # Make sure object is hashable.
+    hash(obj)
+    return obj