Allow scroll events to open custom launcher pages.

ui/app_list/views/start_page_view.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_APP_LIST_VIEWS_START_PAGE_VIEW_H_
 #define UI_APP_LIST_VIEWS_START_PAGE_VIEW_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
@@ skipping 18 matching lines @@
   void Reset();
 
   void UpdateForTesting();
 
   const std::vector<SearchResultTileItemView*>& tile_views() const;
   TileItemView* all_apps_button() const;
 
   // Called when the start page view is displayed.
   void OnShow();
 
-  // Called when the start page view is hidden (while the app list is still
-  // open).
-  void OnHide();
-
   // Overridden from views::View:
   void Layout() override;
   bool OnKeyPressed(const ui::KeyEvent& event) override;
 
+  bool OnMousePressed(const ui::MouseEvent& event) override;
+  bool OnMouseWheel(const ui::MouseWheelEvent& event) override;
+  void OnGestureEvent(ui::GestureEvent* event) override;
+  void OnScrollEvent(ui::ScrollEvent* event) override;
+
   // Returns search box bounds to use when the start page is active.
   gfx::Rect GetSearchBoxBounds() const;
 
-  // Updates whether the custom page clickzone is visible.
-  void UpdateCustomPageClickzoneVisibility();
-
  private:
   class StartPageTilesContainer;
 
   void InitInstantContainer();
+  void MaybeOpenCustomLauncherPage();
 
   TileItemView* GetTileItemView(size_t index);
 
   // The parent view of ContentsView which is the parent of this view.
   AppListMainView* app_list_main_view_;
 
   AppListViewDelegate* view_delegate_;  // Owned by AppListView.
 
   views::View* search_box_spacer_view_;  // Owned by views hierarchy.
   views::View* instant_container_;  // Owned by views hierarchy.
   StartPageTilesContainer* tiles_container_;  // Owned by views hierarchy.
 
   DISALLOW_COPY_AND_ASSIGN(StartPageView);
 };
 
 }  // namespace app_list
 
 #endif  // UI_APP_LIST_VIEWS_START_PAGE_VIEW_H_