Gtk3 ui: Add libgtk3ui as a separate build component

chrome/browser/ui/libgtkui/native_theme_gtk2.cc

Index: chrome/browser/ui/libgtkui/native_theme_gtk2.cc
diff --git a/chrome/browser/ui/libgtk2ui/native_theme_gtk2.cc b/chrome/browser/ui/libgtkui/native_theme_gtk2.cc
similarity index 97%
rename from chrome/browser/ui/libgtk2ui/native_theme_gtk2.cc
rename to chrome/browser/ui/libgtkui/native_theme_gtk2.cc
index 9c49727c20695c5eca742550597bbe8bad110013..fa179c4024b26d21a5a99230872997bec2a4d28b 100644
--- a/chrome/browser/ui/libgtk2ui/native_theme_gtk2.cc
+++ b/chrome/browser/ui/libgtkui/native_theme_gtk2.cc
@@ -2,15 +2,15 @@
 // 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"
@@ -22,7 +22,7 @@
 #include "ui/native_theme/native_theme_aura.h"
 #include "ui/native_theme/native_theme_dark_aura.h"
 
-namespace libgtk2ui {
+namespace libgtkui {
 
 namespace {
 
@@ -571,4 +571,4 @@ GtkWidget* NativeThemeGtk2::GetMenuItem() const {
   return fake_menu_item;
 }
 
-}  // namespace libgtk2ui
+}  // namespace libgtkui