Add service name constant for UI service.

services/ui/clipboard/clipboard_unittest.cc

Index: services/ui/clipboard/clipboard_unittest.cc
diff --git a/services/ui/clipboard/clipboard_unittest.cc b/services/ui/clipboard/clipboard_unittest.cc
index 4615491ffbf0d206f9fcf1063316b898dcdd1466..1ea0f73c7b2218f06f423f90b0bb823e6678588e 100644
--- a/services/ui/clipboard/clipboard_unittest.cc
+++ b/services/ui/clipboard/clipboard_unittest.cc
@@ -12,6 +12,7 @@
 #include "services/service_manager/public/cpp/service_context.h"
 #include "services/service_manager/public/cpp/service_test.h"
 #include "services/ui/public/interfaces/clipboard.mojom.h"
+#include "services/ui/public/interfaces/constants.mojom.h"
 
 using mojo::Array;
 using mojo::Map;
@@ -37,7 +38,7 @@ class ClipboardAppTest : public service_manager::test::ServiceTest {
   void SetUp() override {
     ServiceTest::SetUp();
 
-    connector()->ConnectToInterface("ui", &clipboard_);
+    connector()->ConnectToInterface(ui::mojom::kServiceName, &clipboard_);
     ASSERT_TRUE(clipboard_);
   }