Gtk3 ui: Add libgtk3ui as a separate build component

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_LIBGTK2UI_APP_INDICATOR_ICON_MENU_H_
-#define CHROME_BROWSER_UI_LIBGTK2UI_APP_INDICATOR_ICON_MENU_H_
+#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/libgtk2ui/gtk2_signal.h"
+#include "chrome/browser/ui/libgtkui/gtk2_signal.h"
 
 typedef struct _GtkMenu GtkMenu;
 typedef struct _GtkWidget GtkWidget;
 
 namespace ui {
 class MenuModel;
 }
 
-namespace libgtk2ui {
+namespace libgtkui {
 
 // The app indicator icon's menu.
 class AppIndicatorIconMenu {
  public:
   explicit AppIndicatorIconMenu(ui::MenuModel* model);
   virtual ~AppIndicatorIconMenu();
 
   // Sets a menu item at the top of |gtk_menu_| as a replacement for the app
   // indicator icon's click action. |callback| is called when the menu item
   // is activated.
@@ skipping 25 matching lines @@
   // invoked and is assumed to do any necessary processing.
   base::Closure click_action_replacement_callback_;
 
   GtkWidget* gtk_menu_;
 
   bool block_activation_;
 
   DISALLOW_COPY_AND_ASSIGN(AppIndicatorIconMenu);
 };
 
-}  // namespace libgtk2ui
+}  // namespace libgtkui
 
-#endif  // CHROME_BROWSER_UI_LIBGTK2UI_APP_INDICATOR_ICON_MENU_H_
+#endif  // CHROME_BROWSER_UI_LIBGTKUI_APP_INDICATOR_ICON_MENU_H_