Move Singleton and related structs to namespace base

ui/gfx/win/window_impl.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 "ui/gfx/win/window_impl.h"
 
 #include <list>
 
 #include "base/bind.h"
 #include "base/debug/alias.h"
@@ skipping 63 matching lines @@
     base::string16 name;
 
     // The atom identifying the window class.
     ATOM atom;
 
     // The handle of the module containing the window proceedure.
     HMODULE instance;
   };
 
   ClassRegistrar();
-  friend struct DefaultSingletonTraits<ClassRegistrar>;
+  friend struct base::DefaultSingletonTraits<ClassRegistrar>;
 
   typedef std::list<RegisteredClass> RegisteredClasses;
   RegisteredClasses registered_classes_;
 
   // Counter of how many classes have been registered so far.
   int registered_count_;
 
   base::Lock lock_;
 
   DISALLOW_COPY_AND_ASSIGN(ClassRegistrar);
 };
 
 ClassRegistrar::~ClassRegistrar() {}
 
 // static
 ClassRegistrar* ClassRegistrar::GetInstance() {
-  return Singleton<ClassRegistrar,
-      LeakySingletonTraits<ClassRegistrar> >::get();
+  return base::Singleton<ClassRegistrar,
+                         base::LeakySingletonTraits<ClassRegistrar>>::get();
 }
 
 void ClassRegistrar::UnregisterClasses() {
   for (RegisteredClasses::iterator i = registered_classes_.begin();
         i != registered_classes_.end(); ++i) {
      if (UnregisterClass(MAKEINTATOM(i->atom), i->instance)) {
        registered_classes_.erase(i);
      } else {
        LOG(ERROR) << "Failed to unregister class " << i->name
                   << ". Error = " << GetLastError();
@@ skipping 194 matching lines @@
 }
 
 ATOM WindowImpl::GetWindowClassAtom() {
   HICON icon = GetDefaultWindowIcon();
   HICON small_icon = GetSmallWindowIcon();
   ClassInfo class_info(initial_class_style(), icon, small_icon);
   return ClassRegistrar::GetInstance()->RetrieveClassAtom(class_info);
 }
 
 }  // namespace gfx