Refactor app list so AppsGridView owns the PaginationModel.

ash/wm/app_list_controller.h

Index: ash/wm/app_list_controller.h
diff --git a/ash/wm/app_list_controller.h b/ash/wm/app_list_controller.h
index 437cbb4a75020127ea3a665255e098f61be96e2d..52e9abe06b2b884df8ccd86a1f3e665f9ebea35a 100644
--- a/ash/wm/app_list_controller.h
+++ b/ash/wm/app_list_controller.h
@@ -22,7 +22,6 @@
 namespace app_list {
 class ApplicationDragAndDropHost;
 class AppListView;
-class PaginationModel;
 }
 
 namespace ui {
@@ -125,8 +124,6 @@ class AppListController : public ui::EventHandler,
   virtual void TransitionStarted() OVERRIDE;
   virtual void TransitionChanged() OVERRIDE;
 
-  scoped_ptr<app_list::PaginationModel> pagination_model_;
-
   // Whether we should show or hide app list widget.
   bool is_visible_;
 
@@ -136,6 +133,10 @@ class AppListController : public ui::EventHandler,
   // The AppListView this class manages, owned by its widget.
   app_list::AppListView* view_;
 
+  // The current page of the AppsGridView of |view_|. This is stored outside of
+  // the view's PaginationModel, so that it persists when the view is destroyed.
+  int current_app_page_;
+
   // Cached bounds of |view_| for snapping back animation after over-scroll.
   gfx::Rect view_bounds_;