[Thumbnails] Injecting TopSites into ThumbnailListSource.

chrome/browser/thumbnails/thumbnail_list_source.h

 // Copyright 2014 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_THUMBNAILS_THUMBNAIL_LIST_SOURCE_H_
 #define CHROME_BROWSER_THUMBNAILS_THUMBNAIL_LIST_SOURCE_H_
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "components/history/core/browser/history_types.h"
 #include "content/public/browser/url_data_source.h"
 
 class Profile;
 
 namespace base {
 class RefCountedMemory;
 }
 
+namespace history {
+class TopSites;
+}
+
 namespace thumbnails {
 class ThumbnailService;
 }
 
 // ThumbnailListSource renders a webpage to list all thumbnails stored in
 // TopSites, along with all associated URLs. The thumbnail images are embedded
 // into the HTML via Base64, so we can easily produce a dump of TopSites and
 // the thumbnails it stores.
 class ThumbnailListSource : public content::URLDataSource {
  public:
   explicit ThumbnailListSource(Profile* profile);
 
   // content::URLDataSource implementation.
   std::string GetSource() const override;
+  // Called on the IO thread.
   void StartDataRequest(
       const std::string& path,
       int render_process_id,
       int render_frame_id,
       const content::URLDataSource::GotDataCallback& callback) override;
+
   std::string GetMimeType(const std::string& path) const override;
   base::MessageLoop* MessageLoopForRequestPath(
       const std::string& path) const override;
   bool ShouldServiceRequest(const net::URLRequest* request) const override;
   bool ShouldReplaceExistingSource() const override;
 
  private:
   ~ThumbnailListSource() override;
 
+  // Called on the IO thread.
   void OnMostVisitedURLsAvailable(
     const content::URLDataSource::GotDataCallback& callback,
     const history::MostVisitedURLList& mvurl_list);
 
   // ThumbnailService.
   scoped_refptr<thumbnails::ThumbnailService> thumbnail_service_;
 
-  // Only used when servicing requests on the UI thread.
-  Profile* const profile_;
+  scoped_refptr<history::TopSites> top_sites_;
 
   // For callbacks may be run after destruction.
   base::WeakPtrFactory<ThumbnailListSource> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ThumbnailListSource);
 };
 
 
 #endif  // CHROME_BROWSER_THUMBNAILS_THUMBNAIL_LIST_SOURCE_H_