Add service name constant for UI service.

ui/views/mus/screen_mus.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This has to be before any other includes, else default is picked up.
 // See base/logging for details on this.
 #define NOTIMPLEMENTED_POLICY 5
 
 #include "ui/views/mus/screen_mus.h"
 
 #include "services/service_manager/public/cpp/connection.h"
 #include "services/service_manager/public/cpp/connector.h"
+#include "services/ui/public/interfaces/constants.mojom.h"
 #include "ui/aura/window.h"
 #include "ui/views/mus/native_widget_mus.h"
 #include "ui/views/mus/screen_mus_delegate.h"
 #include "ui/views/mus/window_manager_frame_values.h"
 
 namespace mojo {
 
 template <>
 struct TypeConverter<views::WindowManagerFrameValues,
                      ui::mojom::FrameDecorationValuesPtr> {
@@ skipping 17 matching lines @@
     : delegate_(delegate), display_manager_observer_binding_(this) {
   display::Screen::SetScreenInstance(this);
 }
 
 ScreenMus::~ScreenMus() {
   DCHECK_EQ(this, display::Screen::GetScreen());
   display::Screen::SetScreenInstance(nullptr);
 }
 
 void ScreenMus::Init(service_manager::Connector* connector) {
-  connector->ConnectToInterface("ui", &display_manager_);
+  connector->ConnectToInterface(ui::mojom::kServiceName, &display_manager_);
 
   display_manager_->AddObserver(
       display_manager_observer_binding_.CreateInterfacePtrAndBind());
 
   // We need the set of displays before we can continue. Wait for it.
   //
   // TODO(rockot): Do something better here. This should not have to block tasks
   // from running on the calling thread. http://crbug.com/594852.
   bool success = display_manager_observer_binding_.WaitForIncomingMethodCall();
 
@@ skipping 84 matching lines @@
   // TODO(kylechar): DisplayList would need to change to handle having no
   // primary display.
   if (primary_display_id == display::Display::kInvalidDisplayID)
     return;
 
   ProcessDisplayChanged(*display_list().FindDisplayById(primary_display_id),
                         true);
 }
 
 }  // namespace views