Allow scroll events to open custom launcher pages.

ui/app_list/views/contents_view.cc

 // Copyright (c) 2012 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.
 
 #include "ui/app_list/views/contents_view.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "base/logging.h"
@@ skipping 512 matching lines @@
   if (!start_page_view_)
     return;
 
   if (new_selected == GetPageIndexForState(AppListModel::STATE_START)) {
     start_page_view_->OnShow();
     // Show or hide the custom page view, based on whether it is enabled.
     if (custom_page_view_) {
       custom_page_view_->SetVisible(
           app_list_main_view_->model()->custom_launcher_page_enabled());
     }
-  } else {
-    start_page_view_->OnHide();
   }
 }
 
 void ContentsView::TransitionStarted() {
 }
 
 void ContentsView::TransitionChanged() {
   UpdatePageBounds();
 }
 
 }  // namespace app_list