Make device serial required in AdbWrapper/DeviceUtils

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 b10ebc68e167bdc0e02abfebf4e4c58930296c1a..fab9f2b4ecac41ad7bdd65b7eda87b02c0e32b0b 100644
--- a/build/android/pylib/utils/mock_calls.py
+++ b/build/android/pylib/utils/mock_calls.py
@@ -122,16 +122,19 @@ class TestCase(unittest.TestCase):
     """
     self._watched.update((call.name, call) for call in calls)
 
-  def watchMethodCalls(self, call):
+  def watchMethodCalls(self, call, ignore=None):
     """Watch all public methods of the target identified by a self.call.
 
     Args:
       call: a self.call instance indetifying an object
+      ignore: a list of public methods to ignore when watching for calls
     """
     target = self.call_target(call)
+    if ignore is None:
+      ignore = []
     self.watchCalls(getattr(call, method)
                     for method in dir(target.__class__)
-                    if not method.startswith('_'))
+                    if not method.startswith('_') and not method in ignore)
 
   def clearWatched(self):
     """Clear the set of watched calls."""