Implementing URL prefix match for history thumbnail cache.

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 "content/public/browser/url_data_source.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 content::URLDataSource {
  public:
-  explicit ThumbnailSource(Profile* profile);
+  ThumbnailSource(Profile* profile, bool prefix_match);
 
   // content::URLDataSource implementation.
   virtual std::string GetSource() const OVERRIDE;
   virtual void StartDataRequest(
       const std::string& path,
       int render_process_id,
       int render_view_id,
       const content::URLDataSource::GotDataCallback& callback) OVERRIDE;
   virtual std::string GetMimeType(const std::string& path) const OVERRIDE;
   virtual base::MessageLoop* MessageLoopForRequestPath(
       const std::string& path) const OVERRIDE;
   virtual bool ShouldServiceRequest(
       const net::URLRequest* request) const OVERRIDE;
 
  private:
   virtual ~ThumbnailSource();
 
   // 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_;
 
   // Only used when servicing requests on the UI thread.
   Profile* const profile_;
 
+  // If an exact thumbnail URL match fails, specifies whether or not to try
+  // harder by matching the query thumbnail URL as URL prefix. This affects
+  // GetSource().
+  const bool prefix_match_;
+
   DISALLOW_COPY_AND_ASSIGN(ThumbnailSource);
 };
 
 #endif  // CHROME_BROWSER_UI_WEBUI_NTP_THUMBNAIL_SOURCE_H_