Don't derive from ChromeURLDataManager::DataSource, and instead have these classes implement a dele…

chrome/browser/ui/webui/ntp/thumbnail_source.h

 // 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.
 
 #ifndef CHROME_BROWSER_UI_WEBUI_NTP_THUMBNAIL_SOURCE_H_
 #define CHROME_BROWSER_UI_WEBUI_NTP_THUMBNAIL_SOURCE_H_
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
-#include "chrome/browser/ui/webui/chrome_url_data_manager.h"
+#include "content/public/browser/url_data_source_delegate.h"
 
 class Profile;
 
 namespace base {
 class RefCountedMemory;
 }
 
 namespace thumbnails {
 class ThumbnailService;
 }
 
 // ThumbnailSource is the gateway between network-level chrome: requests for
 // thumbnails and the history/top-sites backend that serves these.
-class ThumbnailSource : public ChromeURLDataManager::DataSource {
+class ThumbnailSource : public content::URLDataSourceDelegate {
  public:
   explicit ThumbnailSource(Profile* profile);
 
-  // Called when the network layer has requested a resource underneath
-  // the path we registered.
+  // content::URLDataSourceDelegate implementation.
+  virtual std::string GetSource() OVERRIDE;
   virtual void StartDataRequest(const std::string& path,
                                 bool is_incognito,
                                 int request_id) OVERRIDE;
-
   virtual std::string GetMimeType(const std::string& path) const OVERRIDE;
-
   virtual MessageLoop* MessageLoopForRequestPath(
       const std::string& path) const OVERRIDE;
 
  private:
   virtual ~ThumbnailSource();
 
   // Send the default thumbnail when we are missing a real one.
   void SendDefaultThumbnail(int request_id);
 
   // Raw PNG representation of the thumbnail to show when the thumbnail
   // database doesn't have a thumbnail for a webpage.
   scoped_refptr<base::RefCountedMemory> default_thumbnail_;
 
   // ThumbnailService.
   scoped_refptr<thumbnails::ThumbnailService> thumbnail_service_;
 
   DISALLOW_COPY_AND_ASSIGN(ThumbnailSource);
 };
 
 #endif  // CHROME_BROWSER_UI_WEBUI_NTP_THUMBNAIL_SOURCE_H_