Gtk3 ui: Add libgtk3ui as a separate build component

chrome/browser/ui/libgtkui/native_theme_gtk2.cc

 // 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.
 
-#include "chrome/browser/ui/libgtk2ui/native_theme_gtk2.h"
+#include "chrome/browser/ui/libgtkui/native_theme_gtk2.h"
 
 #include <gtk/gtk.h>
 
-#include "chrome/browser/ui/libgtk2ui/chrome_gtk_frame.h"
-#include "chrome/browser/ui/libgtk2ui/chrome_gtk_menu_subclasses.h"
-#include "chrome/browser/ui/libgtk2ui/gtk2_ui.h"
-#include "chrome/browser/ui/libgtk2ui/gtk2_util.h"
-#include "chrome/browser/ui/libgtk2ui/skia_utils_gtk2.h"
+#include "chrome/browser/ui/libgtkui/chrome_gtk_frame.h"
+#include "chrome/browser/ui/libgtkui/chrome_gtk_menu_subclasses.h"
+#include "chrome/browser/ui/libgtkui/gtk2_ui.h"
+#include "chrome/browser/ui/libgtkui/gtk2_util.h"
+#include "chrome/browser/ui/libgtkui/skia_utils_gtk2.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/gfx/color_palette.h"
 #include "ui/gfx/color_utils.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/geometry/size.h"
 #include "ui/gfx/path.h"
 #include "ui/gfx/skia_util.h"
 #include "ui/native_theme/common_theme.h"
 #include "ui/native_theme/native_theme_aura.h"
 #include "ui/native_theme/native_theme_dark_aura.h"
 
-namespace libgtk2ui {
+namespace libgtkui {
 
 namespace {
 
 // Theme colors returned by GetSystemColor().
 const SkColor kInvalidColorIdColor = SkColorSetRGB(255, 0, 128);
 const SkColor kURLTextColor = SkColorSetRGB(0x0b, 0x80, 0x43);
 
 // Generates the normal URL color, a green color used in unhighlighted URL
 // text. It is a mix of |kURLTextColor| and the current text color.  Unlike the
 // selected text color, it is more important to match the qualities of the
@@ skipping 528 matching lines @@
   static GtkWidget* fake_menu_item = NULL;
 
   if (!fake_menu_item) {
     fake_menu_item = gtk_custom_menu_item_new();
     gtk_menu_shell_append(GTK_MENU_SHELL(GetMenu()), fake_menu_item);
   }
 
   return fake_menu_item;
 }
 
-}  // namespace libgtk2ui
+}  // namespace libgtkui