Update from https://crrev.com/316786

build/android/pylib/utils/mock_calls.py

Index: build/android/pylib/utils/mock_calls.py
diff --git a/build/android/pylib/utils/mock_calls.py b/build/android/pylib/utils/mock_calls.py
index fab9f2b4ecac41ad7bdd65b7eda87b02c0e32b0b..3052b0d34a4e6a33ee1506448c119d165c9033b3 100644
--- a/build/android/pylib/utils/mock_calls.py
+++ b/build/android/pylib/utils/mock_calls.py
@@ -110,7 +110,12 @@ class TestCase(unittest.TestCase):
     if call.name.startswith('self.'):
       target = self.call_target(call.parent)
       _, attribute = call.name.rsplit('.', 1)
-      return mock.patch.object(target, attribute, **kwargs)
+      if (hasattr(type(target), attribute)
+          and isinstance(getattr(type(target), attribute), property)):
+        return mock.patch.object(
+            type(target), attribute, new_callable=mock.PropertyMock, **kwargs)
+      else:
+        return mock.patch.object(target, attribute, **kwargs)
     else:
       return mock.patch(call.name, **kwargs)