[MD] Change appearance of incognito NTP to MD spec.

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 "chrome/browser/ui/webui/ntp/new_tab_ui.h"
 
 #include <set>
 
 #include "base/i18n/rtl.h"
 #include "base/lazy_instance.h"
@@ skipping 90 matching lines @@
     // We might not have an ExtensionService (on ChromeOS when not logged in
     // for example).
     if (service)
       web_ui->AddMessageHandler(new AppLauncherHandler(service));
   }
 
 #if defined(ENABLE_THEMES)
   // The theme handler can require some CPU, so do it after hooking up the most
   // visited handler. This allows the DB query for the new tab thumbs to happen
   // earlier.
-  web_ui->AddMessageHandler(new ThemeHandler());
+  if (!profile->IsGuestSession())
+    web_ui->AddMessageHandler(new ThemeHandler());
 #endif
 
   scoped_ptr<NewTabHTMLSource> html_source(
       new NewTabHTMLSource(profile->GetOriginalProfile()));
 
   // content::URLDataSource assumes the ownership of the html_source.
   content::URLDataSource::Add(profile, html_source.release());
 
   pref_change_registrar_.Init(profile->GetPrefs());
   pref_change_registrar_.Add(bookmarks::prefs::kShowBookmarkBar,
@@ skipping 218 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() {}