Fix app list duplication on drag.

ui/app_list/views/app_list_main_view_unittest.cc

Index: ui/app_list/views/app_list_main_view_unittest.cc
diff --git a/ui/app_list/views/app_list_main_view_unittest.cc b/ui/app_list/views/app_list_main_view_unittest.cc
index 0091e06f2023d53b93107425062a5e6e6ead484c..9de87fdc51eea3c376c779d14c11dede4f43397a 100644
--- a/ui/app_list/views/app_list_main_view_unittest.cc
+++ b/ui/app_list/views/app_list_main_view_unittest.cc
@@ -264,12 +264,9 @@ TEST_F(AppListMainViewTest, DragLastItemFromFolderAndDropAtLastSlot) {
   drop_target_tile.Offset(first_slot_tile.width() * 2, 0);
   gfx::Point point = drop_target_tile.CenterPoint();
   SimulateUpdateDrag(FolderGridView(), AppsGridView::MOUSE, dragged, point);
-  SimulateUpdateDrag(FolderGridView(), AppsGridView::MOUSE, dragged, point);
-  base::RunLoop().RunUntilIdle();
 
   // Drop it.
   FolderGridView()->EndDrag(false);
-  base::RunLoop().RunUntilIdle();
 
   // Folder icon view should be gone and there is only one item view.
   EXPECT_EQ(1, RootViewModel()->view_size());
@@ -286,6 +283,35 @@ TEST_F(AppListMainViewTest, DragLastItemFromFolderAndDropAtLastSlot) {
             delegate_->GetTestModel()->FindFolderItem("single_item_folder"));
 }
 
+// Tests dragging an item out of a single item folder and dropping it onto the
+// page switcher. Regression test for http://crbug.com/415530/.
+TEST_F(AppListMainViewTest, DragReparentItemOntoPageSwitcher) {
+  AppListItemView* folder_item_view = CreateAndOpenSingleItemFolder();
+  const gfx::Rect first_slot_tile = folder_item_view->bounds();
+
+  delegate_->GetTestModel()->PopulateApps(20);
+
+  EXPECT_EQ(1, FolderViewModel()->view_size());
+  EXPECT_EQ(21, RootViewModel()->view_size());
+
+  AppListItemView* dragged = StartDragForReparent(0);
+
+  gfx::Rect main_view_bounds = main_view_->bounds();
+  // Drag the reparent item to the page switcher.
+  gfx::Point point =
+      gfx::Point(main_view_bounds.width() / 2,
+                 main_view_bounds.bottom() - first_slot_tile.height());
+  SimulateUpdateDrag(FolderGridView(), AppsGridView::MOUSE, dragged, point);
+
+  // Drop it.
+  FolderGridView()->EndDrag(false);
+
+  // The folder should be destroyed.
+  EXPECT_EQ(21, RootViewModel()->view_size());
+  EXPECT_EQ(NULL,
+            delegate_->GetTestModel()->FindFolderItem("single_item_folder"));
+}
+
 // Test that an interrupted drag while reparenting an item from a folder, when
 // canceled via the root grid, correctly forwards the cancelation to the drag
 // ocurring from the folder.