Update display::Display::kInvalidDisplayID constant.

ui/display/display.h

Index: ui/display/display.h
diff --git a/ui/display/display.h b/ui/display/display.h
index 1a8ebcf42ddb43bfb469205582f8e87fc4713a85..9980057e066c3dd2a1a31000480ec33d5b6c5bd9 100644
--- a/ui/display/display.h
+++ b/ui/display/display.h
@@ -66,10 +66,6 @@ class DISPLAY_EXPORT Display final {
     TOUCH_SUPPORT_UNAVAILABLE,
   };
 
-  // Use display::kInvalidDisplayId from display_constants.h in new code.
-  // TODO(kylechar): Delete after all references are gone.
-  enum : int64_t { kInvalidDisplayID = display::kInvalidDisplayId };
-
   // Creates a display with kInvalidDisplayId as default.
   Display();
   explicit Display(int64_t id);