ui/views: convert usage of FOR_EACH_OBSERVER macro

ui/views/widget/desktop_aura/x11_desktop_handler.cc

Index: ui/views/widget/desktop_aura/x11_desktop_handler.cc
diff --git a/ui/views/widget/desktop_aura/x11_desktop_handler.cc b/ui/views/widget/desktop_aura/x11_desktop_handler.cc
index 6f4d6630284681a60fd7d9f6dbf091492e3e422e..0e9dec7673741093d2c44d9cc580b8c5b470cef9 100644
--- a/ui/views/widget/desktop_aura/x11_desktop_handler.cc
+++ b/ui/views/widget/desktop_aura/x11_desktop_handler.cc
@@ -94,8 +94,8 @@ uint32_t X11DesktopHandler::DispatchEvent(const ui::PlatformEvent& event) {
       if (event->xproperty.atom ==
           atom_cache_.GetAtom("_NET_CURRENT_DESKTOP")) {
         if (UpdateWorkspace()) {
-          FOR_EACH_OBSERVER(views::X11DesktopHandlerObserver, observers_,
-                            OnWorkspaceChanged(workspace_));
+          for (views::X11DesktopHandlerObserver& observer : observers_)
+            observer.OnWorkspaceChanged(workspace_);
         }
       }
       break;