New AppListView Scroll Behavior.

ui/app_list/views/search_box_view.h

Index: ui/app_list/views/search_box_view.h
diff --git a/ui/app_list/views/search_box_view.h b/ui/app_list/views/search_box_view.h
index a8e84865464817ae3bf6165df1722ea869930271..ae7b2e3992993257bf1c9bea4526f04b6c7ae3c1 100644
--- a/ui/app_list/views/search_box_view.h
+++ b/ui/app_list/views/search_box_view.h
@@ -85,6 +85,7 @@ class APP_LIST_EXPORT SearchBoxView : public views::View,
   void ShowBackOrGoogleIcon(bool show_back_button);
 
   // Overridden from views::View:
+  void OnMouseEvent(ui::MouseEvent* event) override;
   bool OnMouseWheel(const ui::MouseWheelEvent& event) override;
   void OnEnabledChanged() override;
   const char* GetClassName() const override;
@@ -101,6 +102,8 @@ class APP_LIST_EXPORT SearchBoxView : public views::View,
                        const base::string16& new_contents) override;
   bool HandleKeyEvent(views::Textfield* sender,
                       const ui::KeyEvent& key_event) override;
+  bool HandleMouseEvent(views::Textfield* sender,
+                        const ui::MouseEvent& mouse_event) override;
 
   // Overridden from views::ButtonListener:
   void ButtonPressed(views::Button* sender, const ui::Event& event) override;