Gtk3 ui: Add libgtk3ui as a separate build component

chrome/browser/ui/libgtkui/gtk2_key_bindings_handler.cc

 // Copyright (c) 2012 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.
 
-#include "chrome/browser/ui/libgtk2ui/gtk2_key_bindings_handler.h"
+#include "chrome/browser/ui/libgtkui/gtk2_key_bindings_handler.h"
 
 #include <gdk/gdkkeysyms.h>
 #include <X11/Xlib.h>
 #include <stddef.h>
 #include <X11/XKBlib.h>
 
 #include <string>
 
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/strings/string_util.h"
-#include "chrome/browser/ui/libgtk2ui/gtk2_util.h"
+#include "chrome/browser/ui/libgtkui/gtk2_util.h"
 #include "content/public/browser/native_web_keyboard_event.h"
 #include "ui/base/ime/text_edit_commands.h"
 #include "ui/base/x/x11_util.h"
 #include "ui/events/event.h"
 
 using ui::TextEditCommand;
 
 // TODO(erg): Rewrite the old gtk_key_bindings_handler_unittest.cc and get them
 // in a state that links. This code was adapted from the content layer GTK
 // code, which had some simple unit tests. However, the changes in the public
 // interface basically meant the tests need to be rewritten; this imposes weird
-// linking requirements regarding GTK+ as we don't have a libgtk2ui_unittests
+// linking requirements regarding GTK+ as we don't have a libgtkui_unittests
 // yet. http://crbug.com/358297.
 
-namespace libgtk2ui {
+namespace libgtkui {
 
 Gtk2KeyBindingsHandler::Gtk2KeyBindingsHandler()
     : fake_window_(gtk_offscreen_window_new()),
       handler_(CreateNewHandler()),
       has_xkb_(false) {
   gtk_container_add(GTK_CONTAINER(fake_window_), handler_);
 
   int opcode, event, error;
   int major = XkbMajorVersion;
   int minor = XkbMinorVersion;
@@ skipping 386 matching lines @@
                                           GtkWidgetHelpType arg1) {
   // Just for disabling the default handler.
   return FALSE;
 }
 
 void Gtk2KeyBindingsHandler::MoveFocus(GtkWidget* widget,
                                        GtkDirectionType arg1) {
   // Just for disabling the default handler.
 }
 
-}  // namespace libgtk2ui
+}  // namespace libgtkui