Do not EASE_IN_OUT after fling, rather EASE_OUT.

athena/home/athena_start_page_view.h

Index: athena/home/athena_start_page_view.h
diff --git a/athena/home/athena_start_page_view.h b/athena/home/athena_start_page_view.h
index 236ca567006c6e7b19f12b540da69c7444784b5c..fda3ab6de74acc0e247ccda9471789fdda04bd71 100644
--- a/athena/home/athena_start_page_view.h
+++ b/athena/home/athena_start_page_view.h
@@ -8,6 +8,7 @@
 #include "athena/athena_export.h"
 #include "base/memory/weak_ptr.h"
 #include "ui/app_list/views/search_box_view_delegate.h"
+#include "ui/gfx/animation/tween.h"
 #include "ui/views/view.h"
 
 namespace app_list {
@@ -33,7 +34,8 @@ class ATHENA_EXPORT AthenaStartPageView
 
   // Updates the layout state and move the subviews to the target location with
   // animation.
-  void SetLayoutStateWithAnimation(float layout_state);
+  void SetLayoutStateWithAnimation(float layout_state,
+                                   gfx::Tween::Type tween_type);
 
  private:
   friend class AthenaStartPageViewTest;