Makes a handful of DataSources not replace the existing

chrome/browser/dom_ui/web_ui_theme_source.cc

 // Copyright (c) 2011 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/dom_ui/web_ui_theme_source.h"
 
 #include "base/message_loop.h"
 #include "base/ref_counted_memory.h"
 #include "chrome/browser/browser_thread.h"
 #include "chrome/browser/dom_ui/ntp_resource_cache.h"
@@ skipping 76 matching lines @@
   }
 
   // If it's not a themeable image, we don't need to go to the UI thread.
   int resource_id = ResourcesUtil::GetThemeResourceId(uncached_path);
   if (!BrowserThemeProvider::IsThemeableImage(resource_id))
     return NULL;
 
   return DataSource::MessageLoopForRequestPath(path);
 }
 
+bool WebUIThemeSource::ShouldReplaceExistingSource() const {
+  return false;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // WebUIThemeSource, private:
 
 void WebUIThemeSource::SendThemeBitmap(int request_id, int resource_id) {
   if (BrowserThemeProvider::IsThemeableImage(resource_id)) {
     DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
     ui::ThemeProvider* tp = profile_->GetThemeProvider();
     DCHECK(tp);
 
     scoped_refptr<RefCountedMemory> image_data(tp->GetRawData(resource_id));
     SendResponse(request_id, image_data);
   } else {
     DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
     const ResourceBundle& rb = ResourceBundle::GetSharedInstance();
     SendResponse(request_id, rb.LoadDataResourceBytes(resource_id));
   }
 }