mash: Replace ShelfItemDelegate::CanPin with ShelfItem::pinned_by_policy.

ash/common/shelf/shelf_view.cc

Index: ash/common/shelf/shelf_view.cc
diff --git a/ash/common/shelf/shelf_view.cc b/ash/common/shelf/shelf_view.cc
index f85e154d9afd5d624384a0ff9b3e426de97b7681..5a6bfaa6263e7e25ce84b25744ba31734f18d7d1 100644
--- a/ash/common/shelf/shelf_view.cc
+++ b/ash/common/shelf/shelf_view.cc
@@ -1351,12 +1351,11 @@ ShelfView::RemovableState ShelfView::RemovableByRipOff(int index) const {
   if (type == TYPE_APP_LIST || type == TYPE_DIALOG)
     return NOT_REMOVABLE;
 
-  std::string app_id = delegate_->GetAppIDForShelfID(model_->items()[index].id);
-  ShelfItemDelegate* item_delegate =
-      model_->GetShelfItemDelegate(model_->items()[index].id);
-  if (!item_delegate->CanPin())
+  if (model_->items()[index].pinned_by_policy)
     return NOT_REMOVABLE;
+
   // Note: Only pinned app shortcuts can be removed!
+  std::string app_id = delegate_->GetAppIDForShelfID(model_->items()[index].id);
   return (type == TYPE_APP_SHORTCUT && delegate_->IsAppPinned(app_id))
              ? REMOVABLE
              : DRAGGABLE;