Move Singleton and related structs to namespace base

ui/accessibility/platform/atk_util_auralinux.cc

 // Copyright 2015 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 <atk/atk.h>
 #if defined(USE_GCONF)
 #include <gconf/gconf-client.h>
 #endif
 #include <glib-2.0/gmodule.h>
 
@@ skipping 118 matching lines @@
 G_END_DECLS
 
 //
 // AtkUtilAuraLinuxClass implementation.
 //
 
 namespace ui {
 
 // static
 AtkUtilAuraLinux* AtkUtilAuraLinux::GetInstance() {
-  return Singleton<AtkUtilAuraLinux>::get();
+  return base::Singleton<AtkUtilAuraLinux>::get();
 }
 
 AtkUtilAuraLinux::AtkUtilAuraLinux() {
 }
 
 void AtkUtilAuraLinux::Initialize(
     scoped_refptr<base::TaskRunner> /* init_task_runner */) {
   // TODO(k.czech): use |init_task_runner| to post a task to do the
   // initialization rather than doing it on this thread.
   // http://crbug.com/468112
@@ skipping 23 matching lines @@
   if (g_module_symbol(bridge, "gnome_accessibility_module_init",
                       (gpointer *)&gnome_accessibility_module_init)) {
     (*gnome_accessibility_module_init)();
   }
 }
 
 AtkUtilAuraLinux::~AtkUtilAuraLinux() {
 }
 
 }  // namespace ui