Remove ImageLoadingTracker class

chrome/browser/ui/ash/app_icon_loader_impl.h

 // Copyright (c) 2013 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_ASH_APP_ICON_LOADER_IMPL_H_
 #define CHROME_BROWSER_UI_ASH_APP_ICON_LOADER_IMPL_H_
 
 #include <map>
 #include <string>
 
 #include "chrome/browser/extensions/extension_icon_image.h"
 #include "chrome/browser/ui/ash/app_icon_loader.h"
 
 class Profile;
 
 namespace extensions {
 class Extension;
 }
 
 namespace ash {
 
 // Default implementation of ash::AppIconLoader that interacts with the
-// ExtensionService and ImageLoadingTracker to load images.
+// ExtensionService and ImageLoader to load images.
 class AppIconLoaderImpl : public AppIconLoader,
                           public extensions::IconImage::Observer {
  public:
   AppIconLoaderImpl(Profile* profile, int icon_size,
                     AppIconLoader::Delegate* delegate);
   virtual ~AppIconLoaderImpl();
 
   // AppIconLoader overrides:
   virtual void FetchImage(const std::string& id) OVERRIDE;
   virtual void ClearImage(const std::string& id) OVERRIDE;
@@ skipping 18 matching lines @@
   ImageToExtensionIDMap map_;
 
   const int icon_size_;
 
   DISALLOW_COPY_AND_ASSIGN(AppIconLoaderImpl);
 };
 
 }  // namespace ash
 
 #endif  // CHROME_BROWSER_UI_ASH_APP_ICON_LOADER_IMPL_H_