aura: Make the Linux version of IconLoader not require GTK+.

chrome/browser/icon_loader.h

 // Copyright (c) 2011 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_ICON_LOADER_H_
 #define CHROME_BROWSER_ICON_LOADER_H_
 #pragma once
 
 #include "build/build_config.h"
 
@@ skipping 62 matching lines @@
   scoped_refptr<base::MessageLoopProxy> target_message_loop_;
 
   IconGroupID group_;
 
   IconSize icon_size_;
 
   scoped_ptr<gfx::Image> image_;
 
   Delegate* delegate_;
 
-#if defined(TOOLKIT_USES_GTK)
-  // On X11 we use gdk's pixbuf loader, which has to execute on the UI
-  // thread, so we only read the file on the background thread and parse it
-  // on the main thread.
-  void ParseIcon();
-  FilePath filename_;
-  std::string icon_data_;
-#endif
-
   DISALLOW_COPY_AND_ASSIGN(IconLoader);
 };
 
 #endif  // CHROME_BROWSER_ICON_LOADER_H_