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..a5149973feaff2568c2fbb92c4875b35be12c3fc 100644
--- a/ui/app_list/views/app_list_main_view_unittest.cc
+++ b/ui/app_list/views/app_list_main_view_unittest.cc
@@ -286,6 +286,39 @@ 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();
+
+  const int kInitialApps = 20;

[tapted, 2014/09/22 06:47:02]

nit: I'd just drop this var and put 20 on the next line (also, sky taught me
recently that function-local consts don't get special treatment :), so if you
want to keep it, kInitialApps -> initial_apps)

[calamity, 2014/09/23 01:06:22]

Done.

+  delegate_->GetTestModel()->PopulateApps(kInitialApps);
+
+  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);

[tapted, 2014/09/22 06:47:02]

Why two? (comment?). But I'm pretty sure you can drop one, since the drag is
already ongoing at this point (only StartDragForReparent needs two)

[calamity, 2014/09/23 01:06:22]

Indeed.

+  SimulateUpdateDrag(FolderGridView(), AppsGridView::MOUSE, dragged, point);
+  base::RunLoop().RunUntilIdle();

[tapted, 2014/09/22 06:47:02]

yeah - as discussed - probably don't need these.

[calamity, 2014/09/23 01:06:22]

Done.

+
+  // Drop it.
+  FolderGridView()->EndDrag(false);
+  base::RunLoop().RunUntilIdle();
+
+  // 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.