Refactor extension app icon.

chrome/browser/notifications/application_notifier_source.h

 // Copyright (c) 2016 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_NOTIFICATIONS_APPLICATION_NOTIFIER_SOURCE_H_
 #define CHROME_BROWSER_NOTIFICATIONS_APPLICATION_NOTIFIER_SOURCE_H_
 
-#include "chrome/browser/extensions/extension_app_icon_loader.h"
 #include "chrome/browser/notifications/notifier_source.h"
+#include "chrome/browser/ui/app_icon_loader_delegate.h"
+
+class AppIconLoader;
 
 class ApplicationNotifierSource : public NotifierSource,
                                   public AppIconLoaderDelegate {
  public:
   explicit ApplicationNotifierSource(Observer* observer);
   ~ApplicationNotifierSource() override;
 
   std::vector<std::unique_ptr<message_center::Notifier>> GetNotifierList(
       Profile* profile) override;
 
   void SetNotifierEnabled(Profile* profile,
                           const message_center::Notifier& notifier,
                           bool enabled) override;
 
   message_center::NotifierId::NotifierType GetNotifierType() override;
 
  private:
   // Overridden from AppIconLoaderDelegate.
   void OnAppImageUpdated(const std::string& id,
                          const gfx::ImageSkia& image) override;
 
   std::unique_ptr<AppIconLoader> app_icon_loader_;
 
   // Lifetime of parent must be longer than the source.
   Observer* observer_;
 };
 
 #endif  // CHROME_BROWSER_NOTIFICATIONS_APPLICATION_NOTIFIER_SOURCE_H_