Add service name constant for UI service.

services/ui/ime/ime_unittest.cc

Index: services/ui/ime/ime_unittest.cc
diff --git a/services/ui/ime/ime_unittest.cc b/services/ui/ime/ime_unittest.cc
index 16a338eb3f0e54f80eb34ba5b1433fd7e8472856..6ea877e8d9193c96c6010162b4cdfe796129dce2 100644
--- a/services/ui/ime/ime_unittest.cc
+++ b/services/ui/ime/ime_unittest.cc
@@ -10,6 +10,7 @@
 #include "mojo/public/cpp/bindings/interface_request.h"
 #include "services/service_manager/public/cpp/service_context.h"
 #include "services/service_manager/public/cpp/service_test.h"
+#include "services/ui/public/interfaces/constants.mojom.h"
 #include "services/ui/public/interfaces/ime.mojom.h"
 #include "ui/events/event.h"
 
@@ -52,7 +53,7 @@ class IMEAppTest : public service_manager::test::ServiceTest {
     ServiceTest::SetUp();
     // test_ime_driver will register itself as the current IMEDriver.
     connector()->Connect("test_ime_driver");
-    connector()->ConnectToInterface("ui", &ime_server_);
+    connector()->ConnectToInterface(ui::mojom::kServiceName, &ime_server_);
   }
 
   bool ProcessKeyEvent(ui::mojom::InputMethodPtr* input_method,