Bug 965782 - ignore certain delete_session exceptions in Marionette cleanup, r=wlach

testing/marionette/client/marionette/marionette.py

@@ -517,7 +517,14 @@ class Marionette(object):
 
     def cleanup(self):
         if self.session:
-            self.delete_session()
+            try:
+                self.delete_session()
+            except (MarionetteException, socket.error):
+                # These exceptions get thrown if the Marionette server
+                # hit an exception/died or the connection died. We can
+                # do no further server-side cleanup in this case.
+                pass
+            self.session = None
         if self.emulator:
             self.emulator.close()
         if self.instance: