chrome: Cleanup class/struct forward declarations

chrome/browser/ui/views/download/download_shelf_view.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_VIEWS_DOWNLOAD_DOWNLOAD_SHELF_VIEW_H_
 #define CHROME_BROWSER_UI_VIEWS_DOWNLOAD_DOWNLOAD_SHELF_VIEW_H_
 
 #include <stddef.h>
 
 #include <vector>
@@ skipping 12 matching lines @@
 class BrowserView;
 class DownloadItemView;
 
 namespace content {
 class DownloadItem;
 class PageNavigator;
 }
 
 namespace views {
 class ImageButton;
-class ImageView;
 class MdTextButton;
 }
 
 // DownloadShelfView is a view that contains individual views for each download,
 // as well as a close button and a link to show all downloads.
 //
 // DownloadShelfView does not hold an infinite number of download views, rather
 // it'll automatically remove views once a certain point is reached.
 class DownloadShelfView : public views::AccessiblePaneView,
                           public gfx::AnimationDelegate,
@@ skipping 109 matching lines @@
 
   // The window this shelf belongs to.
   BrowserView* parent_;
 
   views::MouseWatcher mouse_watcher_;
 
   DISALLOW_COPY_AND_ASSIGN(DownloadShelfView);
 };
 
 #endif  // CHROME_BROWSER_UI_VIEWS_DOWNLOAD_DOWNLOAD_SHELF_VIEW_H_