Draggable peeking/fullscreen launcher with transparent background.

ui/app_list/views/contents_view.h

Index: ui/app_list/views/contents_view.h
diff --git a/ui/app_list/views/contents_view.h b/ui/app_list/views/contents_view.h
index e620a251e4fa7d0fae58ad955f222def601954e9..0eb3ab127751dd988fd1fa1a1defb98e3ecfb14d 100644
--- a/ui/app_list/views/contents_view.h
+++ b/ui/app_list/views/contents_view.h
@@ -16,6 +16,7 @@
 #include "ui/app_list/app_list_model_observer.h"
 #include "ui/app_list/pagination_model.h"
 #include "ui/app_list/pagination_model_observer.h"
+#include "ui/app_list/views/app_list_view.h"
 #include "ui/views/view.h"
 #include "ui/views/view_model.h"
 
@@ -46,7 +47,8 @@ class APP_LIST_EXPORT ContentsView : public views::View,
                                      public PaginationModelObserver,
                                      public AppListModelObserver {
  public:
-  explicit ContentsView(AppListMainView* app_list_main_view);
+  explicit ContentsView(AppListMainView* app_list_main_view,
+                        AppListView* app_list_view);
   ~ContentsView() override;
 
   // Initialize the pages of the launcher. Should be called after
@@ -200,6 +202,9 @@ class APP_LIST_EXPORT ContentsView : public views::View,
   // Parent view. Owned by the views hierarchy.
   AppListMainView* app_list_main_view_;
 
+  //  Owned by the views hierarchy.
+  AppListView* const app_list_view_;
+
   // Maps State onto |view_model_| indices.
   std::map<AppListModel::State, int> state_to_view_;