Linux: respect use_gconf in Aura

chrome/browser/ui/libgtk2ui/gtk2_ui.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_LIBGTK2UI_GTK2_UI_H_
 #define CHROME_BROWSER_UI_LIBGTK2UI_GTK2_UI_H_
 
 #include <map>
 #include <vector>
 
@@ skipping 167 matching lines @@
   // changes.
   SkColor focus_ring_color_;
   SkColor thumb_active_color_;
   SkColor thumb_inactive_color_;
   SkColor track_color_;
   SkColor active_selection_bg_color_;
   SkColor active_selection_fg_color_;
   SkColor inactive_selection_bg_color_;
   SkColor inactive_selection_fg_color_;
 
+#if defined(USE_GCONF)
   // Currently, the only source of window button configuration. This will
   // change if we ever have to support XFCE's configuration system or KDE's.
   scoped_ptr<GConfTitlebarListener> titlebar_listener_;
+#endif  // defined(USE_GCONF)
 
   // If either of these vectors are non-empty, they represent the current
   // window button configuration.
   std::vector<views::FrameButton> leading_buttons_;
   std::vector<views::FrameButton> trailing_buttons_;
 
   // Objects to notify when the window frame button order changes.
   ObserverList<views::WindowButtonOrderObserver> observer_list_;
 
   // Image cache of lazily created images.
   mutable ImageCache gtk_images_;
 
   DISALLOW_COPY_AND_ASSIGN(Gtk2UI);
 };
 
 }  // namespace libgtk2ui
 
 // Access point to the GTK2 desktop system. This should be the only symbol that
 // is exported in the library; everything else should be used through the
 // interface, because eventually this .so will be loaded through dlopen at
 // runtime so our main binary can conditionally load GTK2 or GTK3 or EFL or
 // QT or whatever.
 LIBGTK2UI_EXPORT views::LinuxUI* BuildGtk2UI();
 
 #endif  // CHROME_BROWSER_UI_LIBGTK2UI_GTK2_UI_H_