Simplify WebUI data sources. Currently WebUI data sources implement a URLDataSourceDelegate interfa…

chrome/browser/ui/webui/fileicon_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_FILEICON_SOURCE_H_
 #define CHROME_BROWSER_UI_WEBUI_FILEICON_SOURCE_H_
 
 #include <string>
 
 #include "base/file_path.h"
 #include "chrome/browser/icon_manager.h"
 #include "chrome/common/cancelable_task_tracker.h"
-#include "content/public/browser/url_data_source_delegate.h"
+#include "content/public/browser/url_data_source.h"
 #include "ui/base/layout.h"
 
 namespace gfx {
 class Image;
 }
 
 // FileIconSource is the gateway between network-level chrome:
 // requests for favicons and the history backend that serves these.
-class FileIconSource : public content::URLDataSourceDelegate {
+class FileIconSource : public content::URLDataSource {
  public:
   explicit FileIconSource();
 
-  // content::URLDataSourceDelegate implementation.
+  // content::URLDataSource implementation.
   virtual std::string GetSource() OVERRIDE;
-  virtual void StartDataRequest(const std::string& path,
-                                bool is_incognito,
-                                int request_id) OVERRIDE;
+  virtual void StartDataRequest(
+      const std::string& path,
+      bool is_incognito,
+      const content::URLDataSource::GotDataCallback& callback) OVERRIDE;
   virtual std::string GetMimeType(const std::string&) const OVERRIDE;
 
  protected:
   virtual ~FileIconSource();
 
   // Once the |path| and |icon_size| has been determined from the request, this
   // function is called to perform the actual fetch. Declared as virtual for
   // testing.
-  virtual void FetchFileIcon(const FilePath& path,
-                             ui::ScaleFactor scale_factor,
-                             IconLoader::IconSize icon_size,
-                             int request_id);
+  virtual void FetchFileIcon(
+      const FilePath& path,
+      ui::ScaleFactor scale_factor,
+      IconLoader::IconSize icon_size,
+      const content::URLDataSource::GotDataCallback& callback);
 
  private:
   // Contains the necessary information for completing an icon fetch request.
   struct IconRequestDetails {
-    // The request id corresponding to these details.
-    int request_id;
+    IconRequestDetails();
+    ~IconRequestDetails();
+
+    // The callback to run with the response.
+    content::URLDataSource::GotDataCallback callback;
 
     // The requested scale factor to respond with.
     ui::ScaleFactor scale_factor;
   };
 
   // Called when favicon data is available from the history backend.
   void OnFileIconDataAvailable(const IconRequestDetails& details,
                                gfx::Image* icon);
 
   // Tracks tasks requesting file icons.
   CancelableTaskTracker cancelable_task_tracker_;
 
   DISALLOW_COPY_AND_ASSIGN(FileIconSource);
 };
 #endif  // CHROME_BROWSER_UI_WEBUI_FILEICON_SOURCE_H_