Remove some unused files in libgtk2ui

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>
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/observer_list.h"
 #include "chrome/browser/ui/libgtk2ui/gtk2_signal.h"
-#include "chrome/browser/ui/libgtk2ui/gtk2_signal_registrar.h"
 #include "chrome/browser/ui/libgtk2ui/libgtk2ui_export.h"
 #include "ui/events/linux/text_edit_key_bindings_delegate_auralinux.h"
 #include "ui/gfx/color_utils.h"
 #include "ui/views/linux_ui/linux_ui.h"
 #include "ui/views/window/frame_buttons.h"
 
 typedef struct _GtkBorder GtkBorder;
 typedef struct _GtkStyle GtkStyle;
 typedef struct _GtkWidget GtkWidget;
 
 class SkBitmap;
 
 namespace gfx {
 class Image;
 }
 
 namespace libgtk2ui {
 class Gtk2Border;
 class Gtk2KeyBindingsHandler;
-class Gtk2SignalRegistrar;
 class GConfListener;
 
 // Interface to GTK2 desktop features.
 //
 class Gtk2UI : public views::LinuxUI {
  public:
   Gtk2UI();
   ~Gtk2UI() override;
 
   typedef base::Callback<ui::NativeTheme*(aura::Window* window)>
@@ skipping 192 matching lines @@
 }  // 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_