Consolidate icon loading on ChromeOS

chrome/browser/ui/webui/fileicon_source.h

-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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_
 #pragma once
 
 #include <string>
 
+#include "base/file_path.h"
 #include "chrome/browser/icon_manager.h"
 #include "chrome/browser/ui/webui/chrome_url_data_manager.h"
 
 class RefCountedBytes;
 
 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 ChromeURLDataManager::DataSource {
  public:
   explicit FileIconSource();
 
   // Called when the network layer has requested a resource underneath
   // the path we registered.
   virtual void StartDataRequest(const std::string& path,
                                 bool is_incognito,
                                 int request_id) OVERRIDE;
 
   virtual std::string GetMimeType(const std::string&) const OVERRIDE;
 
   // Called when favicon data is available from the history backend.
   void OnFileIconDataAvailable(
       IconManager::Handle request_handle,
       gfx::Image* icon);
 
- private:
+ 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,
+                             IconLoader::IconSize icon_size,
+                             int request_id);
+
+ private:
   CancelableRequestConsumerT<int, 0> cancelable_consumer_;
 
-  // Raw PNG representation of the favicon to show when the favicon
-  // database doesn't have a favicon for a webpage.
-  scoped_refptr<RefCountedBytes> default_favicon_;
-
   DISALLOW_COPY_AND_ASSIGN(FileIconSource);
 };
 #endif  // CHROME_BROWSER_UI_WEBUI_FILEICON_SOURCE_H_