Gtk3 UI: Rename files in libgtkui containing gtk2 in their name

chrome/browser/ui/libgtkui/gtk_status_icon.h

 // Copyright 2014 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_LIBGTKUI_GTK2_STATUS_ICON_H_
-#define CHROME_BROWSER_UI_LIBGTKUI_GTK2_STATUS_ICON_H_
+#ifndef CHROME_BROWSER_UI_LIBGTKUI_GTK_STATUS_ICON_H_
+#define CHROME_BROWSER_UI_LIBGTKUI_GTK_STATUS_ICON_H_
 
 #include <memory>
 
 #include "base/macros.h"
 #include "base/strings/string16.h"
-#include "chrome/browser/ui/libgtkui/gtk2_signal.h"
+#include "chrome/browser/ui/libgtkui/gtk_signal.h"
 #include "ui/base/glib/glib_integers.h"
 #include "ui/base/glib/glib_signal.h"
 #include "ui/views/linux_ui/status_icon_linux.h"
 
 typedef struct _GtkStatusIcon GtkStatusIcon;
 
 namespace gfx {
 class ImageSkia;
 }
 
@@ skipping 29 matching lines @@
 
   GtkStatusIcon* gtk_status_icon_;
 
   std::unique_ptr<AppIndicatorIconMenu> menu_;
 
   DISALLOW_COPY_AND_ASSIGN(Gtk2StatusIcon);
 };
 
 }  // namespace libgtkui
 
-#endif  // CHROME_BROWSER_UI_LIBGTKUI_GTK2_STATUS_ICON_H_
+#endif  // CHROME_BROWSER_UI_LIBGTKUI_GTK_STATUS_ICON_H_