Don't show the apps page on the NTP if the app launcher is installed.

chrome/browser/ui/webui/ntp/new_tab_ui.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 "build/build_config.h"
 
 #include "chrome/browser/ui/webui/ntp/new_tab_ui.h"
 
 #include <set>
 
@@ skipping 107 matching lines @@
       web_ui->AddMessageHandler(new NewTabPageSyncHandler());
 
     // Or apps.
     if (ShouldShowApps()) {
       ExtensionService* service = GetProfile()->GetExtensionService();
       // We might not have an ExtensionService (on ChromeOS when not logged in
       // for example).
       if (service)
         web_ui->AddMessageHandler(new AppLauncherHandler(service));
     }
+
+    web_ui->AddMessageHandler(new AppsPagePresenceHandler());
 #endif
 
     web_ui->AddMessageHandler(new FaviconWebUIHandler());
   }
 
 #if defined(OS_ANDROID)
   // These handlers are specific to the Android NTP page.
   web_ui->AddMessageHandler(new BookmarksHandler());
   web_ui->AddMessageHandler(new ContextMenuHandler());
   web_ui->AddMessageHandler(new NewTabPageReadyHandler());
@@ skipping 285 matching lines @@
 void NewTabUI::NewTabHTMLSource::AddResource(const char* resource,
                                              const char* mime_type,
                                              int resource_id) {
   DCHECK(resource);
   DCHECK(mime_type);
   resource_map_[std::string(resource)] =
       std::make_pair(std::string(mime_type), resource_id);
 }
 
 NewTabUI::NewTabHTMLSource::~NewTabHTMLSource() {}