Added --custom-launcher-page. Adds a page to the experimental launcher.

ui/app_list/views/contents_view.cc

Index: ui/app_list/views/contents_view.cc
diff --git a/ui/app_list/views/contents_view.cc b/ui/app_list/views/contents_view.cc
index 1b4e12447eb1e73549cd5da1639ff07d6851d3a3..3dc588e37e67201d4b6ac27978a6cc3eb5745617 100644
--- a/ui/app_list/views/contents_view.cc
+++ b/ui/app_list/views/contents_view.cc
@@ -53,6 +53,11 @@ void ContentsView::InitNamedPages(AppListModel* model,
   DCHECK(model);
 
   if (app_list::switches::IsExperimentalAppListEnabled()) {
+    views::View* custom_page_view =
+        view_delegate->CreateCustomPageWebView(GetLocalBounds().size());
+    if (custom_page_view)
+      AddLauncherPage(custom_page_view, IDR_APP_LIST_NOTIFICATIONS_ICON);
+
     start_page_view_ = new StartPageView(app_list_main_view_, view_delegate);
     AddLauncherPage(
         start_page_view_, IDR_APP_LIST_SEARCH_ICON, NAMED_PAGE_START);