Revert of Draggable peeking/fullscreen launcher with transparent background.

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 b365a44148b14e227d66c69febe3887a1422ab47..5cfa290c5fb7f57ab1944602be04ad963d9ce5fe 100644
--- a/ui/app_list/views/app_list_main_view_unittest.cc
+++ b/ui/app_list/views/app_list_main_view_unittest.cc
@@ -82,7 +82,10 @@
     views::ViewsTestBase::SetUp();
     delegate_.reset(new AppListTestViewDelegate);
 
-    main_view_ = new AppListMainView(delegate_.get(), nullptr);
+    // In Ash, the third argument is a container aura::Window, but it is always
+    // NULL on Windows, and not needed for tests. It is only used to determine
+    // the scale factor for preloading icons.
+    main_view_ = new AppListMainView(delegate_.get());
     main_view_->SetPaintToLayer();
     main_view_->model()->SetFoldersEnabled(true);
     search_box_view_ = new SearchBoxView(main_view_, delegate_.get());