Change mojo enums to be scoped enums in the generated C++ bindings.

components/mus/common/transient_window_utils.h

Index: components/mus/common/transient_window_utils.h
diff --git a/components/mus/common/transient_window_utils.h b/components/mus/common/transient_window_utils.h
index 042e11dd493000f6bea5700e38135975344fc1b1..17eedc63a25a57807fa1d9b989a38300bde2d03b 100644
--- a/components/mus/common/transient_window_utils.h
+++ b/components/mus/common/transient_window_utils.h
@@ -78,7 +78,7 @@ bool AdjustStackingForTransientWindows(T** child,
   FindCommonTransientAncestor(child, target);
 
   // When stacking above skip to the topmost transient descendant of the target.
-  if (*direction == mojom::ORDER_DIRECTION_ABOVE &&
+  if (*direction == mojom::OrderDirection::ABOVE &&
       !HasTransientAncestor(*child, *target)) {
     const std::vector<T*>& siblings((*child)->parent()->children());
     size_t target_i =
@@ -116,7 +116,7 @@ void RestackTransientDescendants(T* window,
     if ((*it) != window && HasTransientAncestor(*it, window)) {
       T* old_stacking_target = *GetStackingTarget(*it);
       *GetStackingTarget(*it) = window;
-      Reorder(*it, window, mojom::ORDER_DIRECTION_ABOVE);
+      Reorder(*it, window, mojom::OrderDirection::ABOVE);
       *GetStackingTarget(*it) = old_stacking_target;
     }
   }