After uninstall, remove last item in Launcher folder

ui/app_list/app_list_model.cc

Index: ui/app_list/app_list_model.cc
diff --git a/ui/app_list/app_list_model.cc b/ui/app_list/app_list_model.cc
index 0a8e0cd33bfc5b8b006eb65fd62d4dbaf375cb41..fd5e2943c988362aa5a7ab034468eb91ace6323f 100644
--- a/ui/app_list/app_list_model.cc
+++ b/ui/app_list/app_list_model.cc
@@ -280,6 +280,26 @@ void AppListModel::DeleteItem(const std::string& id) {
   FOR_EACH_OBSERVER(AppListModelObserver, observers_, OnAppListItemDeleted());
 }
 
+void AppListModel::DeleteUninstalledItem(const std::string& id) {
+  AppListItem* item = FindItem(id);
+  if (!item)
+    return;
+  const std::string folder_id = item->folder_id();
+  DeleteItem(id);
+
+  // Issue 368111: Upon uninstall of 2nd-to-last folder item, reparent last item

[stevenjb, 2015/03/30 17:23:59]

nit: crbug.com/368111:

[Greg Levin, 2015/03/30 23:08:52]

Done.

+  // to top and remove folder.
+  AppListFolderItem* folder = FindFolderItem(folder_id);
+  if (folder && folder->ChildItemCount() == 1u) {
+    FOR_EACH_OBSERVER(AppListModelObserver, observers_,
+                      OnSingleItemFolderWillBeDeleted(folder_id));

[stevenjb, 2015/03/30 17:23:59]

In DeleteItem() we call OnAppListItemWillBeDeleted. This should get called for
folders too. It seems like that method should be able to check for the case of a
folder being deleted and handle any special view logic there.

[Greg Levin, 2015/03/30 23:08:52]

Done.  Thanks for pointing this out.  It turns out that a small modification in
AppsGridView::OnFolderItemRemoved() (called from
AppListFolderView::OnAppListItemWillBeDeleted()) was all that was needed, I just
hadn't found the right spot before.

+
+    // Move last item in model, folder and views will update themselves.
+    AppListItem* last_item = folder->item_list()->item_at(0);
+    MoveItemToFolderAt(last_item, "", folder->position());
+  }
+}
+
 void AppListModel::NotifyExtensionPreferenceChanged() {
   for (size_t i = 0; i < top_level_item_list_->item_count(); ++i)
     top_level_item_list_->item_at(i)->OnExtensionPreferenceChanged();