New AppListView Scroll Behavior.

ui/app_list/views/app_list_view.h

Index: ui/app_list/views/app_list_view.h
diff --git a/ui/app_list/views/app_list_view.h b/ui/app_list/views/app_list_view.h
index 5b7bf2b8a78b1f3c6a30e3d56f78f84582c97fff..fe41bf1ee40e07884500c56a29caf043ec08bbaf 100644
--- a/ui/app_list/views/app_list_view.h
+++ b/ui/app_list/views/app_list_view.h
@@ -136,6 +136,9 @@ class APP_LIST_EXPORT AppListView : public views::BubbleDialogDelegateView,
   // Called when maximize mode starts and ends.
   void OnMaximizeModeChanged(bool started);
 
+  // Changes |app_list_state_| from |PEEKING| to |FULLSCREEN_ALL_APPS|.
+  bool HandleScroll(const ui::Event* event);
+
  private:
   friend class test::AppListViewTestApi;
 
@@ -175,6 +178,7 @@ class APP_LIST_EXPORT AppListView : public views::BubbleDialogDelegateView,
   void GetWidgetHitTestMask(gfx::Path* mask) const override;
 
   // Overridden from ui::EventHandler:
+  void OnScrollEvent(ui::ScrollEvent* event) override;
   void OnMouseEvent(ui::MouseEvent* event) override;
   void OnGestureEvent(ui::GestureEvent* event) override;