Extract a Connector interface from Shell that can be cloned & passed to other threads

mojo/shell/tests/application_manager_unittest.cc

Index: mojo/shell/tests/application_manager_unittest.cc
diff --git a/mojo/shell/tests/application_manager_unittest.cc b/mojo/shell/tests/application_manager_unittest.cc
index 574a2c89720f9363bca1ecadb3dd5976eaf8e1cd..61d8985caeb6d14603646de70e0dc62e89817254 100644
--- a/mojo/shell/tests/application_manager_unittest.cc
+++ b/mojo/shell/tests/application_manager_unittest.cc
@@ -602,7 +602,7 @@ TEST_F(ApplicationManagerTest, TestEndApplicationClosure) {
   scoped_ptr<ConnectParams> params(new ConnectParams);
   params->set_source(CreateShellIdentity());
   params->set_target(
-      Identity(GURL("test:test"), "", mojom::Shell::kUserRoot,
+      Identity(GURL("test:test"), "", mojom::Connector::kUserRoot,
                GetPermissiveCapabilityFilter()));
   application_manager_->SetInstanceQuitCallback(
       base::Bind(&QuitClosure, params->target(), &called));