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

chrome/browser/ui/libgtkui/app_indicator_icon_menu.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_APP_INDICATOR_ICON_MENU_H_
 #define CHROME_BROWSER_UI_LIBGTKUI_APP_INDICATOR_ICON_MENU_H_
 
 #include "base/callback.h"
 #include "base/macros.h"
-#include "chrome/browser/ui/libgtkui/gtk2_signal.h"
+#include "chrome/browser/ui/libgtkui/gtk_signal.h"
 
 typedef struct _GtkMenu GtkMenu;
 typedef struct _GtkWidget GtkWidget;
 
 namespace ui {
 class MenuModel;
 }
 
 namespace libgtkui {
 
@@ skipping 37 matching lines @@
   GtkWidget* gtk_menu_;
 
   bool block_activation_;
 
   DISALLOW_COPY_AND_ASSIGN(AppIndicatorIconMenu);
 };
 
 }  // namespace libgtkui
 
 #endif  // CHROME_BROWSER_UI_LIBGTKUI_APP_INDICATOR_ICON_MENU_H_