Move enum MenuAnchorPosition to reduce deps on menu_item_view.h

ash/shelf/shelf_view.cc

Index: ash/shelf/shelf_view.cc
diff --git a/ash/shelf/shelf_view.cc b/ash/shelf/shelf_view.cc
index 26066f5a4f4850d2ddeb5bbe7a3d6a7790c8843d..1cc1cf61203d2e22519615086d8dfb21a5564d52 100644
--- a/ash/shelf/shelf_view.cc
+++ b/ash/shelf/shelf_view.cc
@@ -1767,8 +1767,7 @@ void ShelfView::ShowMenu(scoped_ptr<views::MenuModelAdapter> menu_model_adapter,
       source->GetWidget()->GetNativeView()->GetRootWindow());
 
   // Determine the menu alignment dependent on the shelf.
-  views::MenuItemView::AnchorPosition menu_alignment =
-      views::MenuItemView::TOPLEFT;
+  views::MenuAnchorPosition menu_alignment = views::MENU_ANCHOR_TOPLEFT;
   gfx::Rect anchor_point = gfx::Rect(click_point, gfx::Size());
 
   ShelfWidget* shelf = RootWindowController::ForShelf(
@@ -1793,16 +1792,16 @@ void ShelfView::ShowMenu(scoped_ptr<views::MenuModelAdapter> menu_model_adapter,
 
     switch (align) {
       case SHELF_ALIGNMENT_BOTTOM:
-        menu_alignment = views::MenuItemView::BUBBLE_ABOVE;
+        menu_alignment = views::MENU_ANCHOR_BUBBLE_ABOVE;
         break;
       case SHELF_ALIGNMENT_LEFT:
-        menu_alignment = views::MenuItemView::BUBBLE_RIGHT;
+        menu_alignment = views::MENU_ANCHOR_BUBBLE_RIGHT;
         break;
       case SHELF_ALIGNMENT_RIGHT:
-        menu_alignment = views::MenuItemView::BUBBLE_LEFT;
+        menu_alignment = views::MENU_ANCHOR_BUBBLE_LEFT;
         break;
       case SHELF_ALIGNMENT_TOP:
-        menu_alignment = views::MenuItemView::BUBBLE_BELOW;
+        menu_alignment = views::MENU_ANCHOR_BUBBLE_BELOW;
         break;
     }
   }