don't display platform app resources in normal browser windows

chrome/browser/extensions/extension_service.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 "chrome/browser/extensions/extension_service.h"
 
 #include <algorithm>
 #include <set>
 
 #include "base/basictypes.h"
@@ skipping 2265 matching lines @@
 }
 
 bool ExtensionService::ExtensionBindingsAllowed(const GURL& url) {
   // Allow bindings for all packaged extensions and component hosted apps.
   const Extension* extension = extensions_.GetExtensionOrAppByURL(
       ExtensionURLInfo(url));
   return extension && (!extension->is_hosted_app() ||
                        extension->location() == Extension::COMPONENT);
 }
 
+bool ExtensionService::ShouldBlockUrlInBrowserTab(GURL* url) {
+  const Extension* extension = extensions_.GetExtensionOrAppByURL(
+      ExtensionURLInfo(*url));
+  if (extension && extension->is_platform_app()) {
+    *url = GURL(chrome::kExtensionInvalidRequestURL);
+    return true;
+  }
+
+  return false;
+}
+
 gfx::Image ExtensionService::GetOmniboxIcon(
     const std::string& extension_id) {
   return gfx::Image(omnibox_icon_manager_.GetIcon(extension_id));
 }
 
 gfx::Image ExtensionService::GetOmniboxPopupIcon(
     const std::string& extension_id) {
   return gfx::Image(omnibox_popup_icon_manager_.GetIcon(extension_id));
 }
 
@@ skipping 370 matching lines @@
                                 extension_host->extension(),
                                 NULL, FilePath());
 #endif
 }
 
 void ExtensionService::InspectExtensionHost(
     extensions::ExtensionHost* host) {
   if (host)
     DevToolsWindow::OpenDevToolsWindow(host->render_view_host());
 }