Revert of Cros Tablet Window management - Split Screen part II

ash/wm/overview/scoped_transform_overview_window.h

Index: ash/wm/overview/scoped_transform_overview_window.h
diff --git a/ash/wm/overview/scoped_transform_overview_window.h b/ash/wm/overview/scoped_transform_overview_window.h
index 83d1812b261a03a7d87fd3e6c99938a1968d3b6f..56b12cf9414ca894b57c5daf68bd9f13bf980caa 100644
--- a/ash/wm/overview/scoped_transform_overview_window.h
+++ b/ash/wm/overview/scoped_transform_overview_window.h
@@ -34,7 +34,6 @@
 namespace ash {
 
 class ScopedOverviewAnimationSettings;
-class WindowSelectorItem;
 
 // Manages a window, and its transient children, in the overview mode. This
 // class allows transforming the windows with a helper to determine the best
@@ -66,8 +65,7 @@
   static gfx::Transform GetTransformForRect(const gfx::Rect& src_rect,
                                             const gfx::Rect& dst_rect);
 
-  ScopedTransformOverviewWindow(WindowSelectorItem* selector_item,
-                                aura::Window* window);
+  explicit ScopedTransformOverviewWindow(aura::Window* window);
   ~ScopedTransformOverviewWindow() override;
 
   // Starts an animation sequence which will use animation settings specified by
@@ -167,9 +165,6 @@
   // Makes Close() execute synchronously when used in tests.
   static void SetImmediateCloseForTests();
 
-  // A weak pointer to the window selector item that owns the transform window.
-  WindowSelectorItem* selector_item_;
-
   // A weak pointer to the real window in the overview.
   aura::Window* window_;