Add keyboard navigation to the custom launcher page on app list start page.

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"
 #include "ui/app_list/app_list_export.h"
 #include "ui/views/view.h"
 
 namespace app_list {
 
 class AllAppsTileItemView;
 class AppListMainView;
 class AppListViewDelegate;
+class CustomLauncherPageBackgroundView;
 class SearchResultTileItemView;
 class TileItemView;
 
 // The start page for the experimental app list.
 class APP_LIST_EXPORT StartPageView : public views::View {
  public:
   StartPageView(AppListMainView* app_list_main_view,
                 AppListViewDelegate* view_delegate);
   ~StartPageView() override;
 
@@ skipping 19 matching lines @@
 
   // Returns search box bounds to use when the start page is active.
   gfx::Rect GetSearchBoxBounds() const;
 
  private:
   class StartPageTilesContainer;
 
   void InitInstantContainer();
   void MaybeOpenCustomLauncherPage();
 
+  void SetCustomLauncherPageSelected(bool selected);
+
   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.
+  CustomLauncherPageBackgroundView*
+      custom_launcher_page_background_;       // Owned by view 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_