Move kInvalidDisplayID to display_constants.h.

ui/display/manager/display_manager_utilities_unittest.cc

Index: ui/display/manager/display_manager_utilities_unittest.cc
diff --git a/ui/display/manager/display_manager_utilities_unittest.cc b/ui/display/manager/display_manager_utilities_unittest.cc
index b82871b141c07499334bd7e7a4af764235650b4a..fc038766e27ea0825cb72dd3d6e17fc15ecfe9ac 100644
--- a/ui/display/manager/display_manager_utilities_unittest.cc
+++ b/ui/display/manager/display_manager_utilities_unittest.cc
@@ -7,16 +7,11 @@
 #include "ui/display/manager/display_manager_utilities.h"
 
 #include "testing/gtest/include/gtest/gtest.h"
-
-//#include "ash/root_window_controller.h"
-//#include "ash/shell.h"
-//#include "ash/test/ash_test_base.h"
-//#include "ash/test/display_manager_test_api.h"
+#include "ui/display/display.h"
+#include "ui/display/types/display_constants.h"
 
 namespace display {
 
-// typedef test::AshTestBase DisplayUtilTest;
-
 namespace {
 
 class ScopedSetInternalDisplayId {
@@ -30,7 +25,7 @@ ScopedSetInternalDisplayId::ScopedSetInternalDisplayId(int64_t id) {
 }
 
 ScopedSetInternalDisplayId::~ScopedSetInternalDisplayId() {
-  display::Display::SetInternalDisplayId(display::Display::kInvalidDisplayID);
+  display::Display::SetInternalDisplayId(kInvalidDisplayID);
 }
 
 }  // namespace