Move enum MenuAnchorPosition to reduce deps on menu_item_view.h

ui/views/examples/tree_view_example.cc

Index: ui/views/examples/tree_view_example.cc
diff --git a/ui/views/examples/tree_view_example.cc b/ui/views/examples/tree_view_example.cc
index e7cce32d0adfa2e76b0847591010c00cbca43325..2f6cc4cedf3a3126f7914164ab0c7f9115a5967c 100644
--- a/ui/views/examples/tree_view_example.cc
+++ b/ui/views/examples/tree_view_example.cc
@@ -132,10 +132,14 @@ void TreeViewExample::ShowContextMenuForView(View* source,
   context_menu_model.AddItem(ID_REMOVE, ASCIIToUTF16("Remove"));
   context_menu_model.AddItem(ID_ADD, ASCIIToUTF16("Add"));
   context_menu_runner_.reset(new MenuRunner(&context_menu_model));
-  if (context_menu_runner_->RunMenuAt(source->GetWidget(), NULL,
-      gfx::Rect(point, gfx::Size()), MenuItemView::TOPLEFT, source_type, 0) ==
-      MenuRunner::MENU_DELETED)
+  if (context_menu_runner_->RunMenuAt(source->GetWidget(),
+                                      NULL,
+                                      gfx::Rect(point, gfx::Size()),
+                                      MENU_ANCHOR_TOPLEFT,
+                                      source_type,
+                                      0) == MenuRunner::MENU_DELETED) {
     return;
+  }
 }
 
 bool TreeViewExample::IsCommandIdChecked(int command_id) const {