Require an explicit ServiceName annotation for interfaces in Python.

mojo/public/python/mojo_application/application_impl.py

Index: mojo/public/python/mojo_application/application_impl.py
diff --git a/mojo/public/python/mojo_application/application_impl.py b/mojo/public/python/mojo_application/application_impl.py
index 80b0376853e512a03f658b32d4a81faa2121e44c..b5758ccb0d2c5574ecf004ec83741c4395f05331 100644
--- a/mojo/public/python/mojo_application/application_impl.py
+++ b/mojo/public/python/mojo_application/application_impl.py
@@ -4,6 +4,8 @@
 
 """Python implementation of the Application interface."""
 
+import logging
+
 import application_mojom
 import service_provider_mojom
 import shell_mojom
@@ -46,12 +48,15 @@ class ApplicationImpl(application_mojom.Application):
     application to be connected to, and |service_class| is the class of the
     service to be connected to. Returns a proxy to the service.
     """
+    if not service_class.service_name:

[qsr, 2015/12/10 15:13:53]

I think service_name should be in the manager class, not on the class itself. We
are trying not to restrict the number of collision that can happen as much as
possible.

+      logging.error("No ServiceName specified for %s." % service_class.__name__)
+      return
     application_proxy, request = (
         service_provider_mojom.ServiceProvider.manager.NewRequest())
     self.shell.ConnectToApplication(application_url, request, None)
 
     service_proxy, request = service_class.manager.NewRequest()
-    application_proxy.ConnectToService(service_class.manager.name,
+    application_proxy.ConnectToService(service_class.service_name,
                                        request.PassMessagePipe())
 
     return service_proxy