Update Windows UI on system color changes.

chrome/browser/ui/libgtk2ui/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 <gtk/gtk.h>
 
 #include "chrome/browser/ui/libgtk2ui/chrome_gtk_menu_subclasses.h"
 #include "chrome/browser/ui/libgtk2ui/skia_utils_gtk2.h"
@@ skipping 153 matching lines @@
           NativeTheme::kColorId_FocusedMenuItemBackgroundColor);
       paint.setColor(color);
       break;
     default:
       NOTREACHED() << "Invalid state " << state;
       break;
   }
   canvas->drawRect(gfx::RectToSkRect(rect), paint);
 }
 
+void NativeThemeGtk2::NotifyNativeThemeObservers() {
+  NotifyObservers();
+}
+
 GdkColor NativeThemeGtk2::GetSystemGdkColor(ColorId color_id) const {
   switch (color_id) {
     // Windows
     case kColorId_WindowBackground:
       return GetWindowStyle()->bg[GTK_STATE_NORMAL];
 
     // Dialogs
     case kColorId_DialogBackground:
       return GetWindowStyle()->bg[GTK_STATE_NORMAL];
 
@@ skipping 204 matching lines @@
       fake_menu_.Own(gtk_custom_menu_new());
 
     fake_menu_item_ = gtk_custom_menu_item_new();
     gtk_menu_shell_append(GTK_MENU_SHELL(fake_menu_.get()), fake_menu_item_);
   }
 
   return gtk_rc_get_style(fake_menu_item_);
 }
 
 }  // namespace libgtk2ui