Move small c/b/extensions classes into extensions namespace no.2

chrome/browser/extensions/shell_window_registry.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 "chrome/browser/extensions/shell_window_registry.h"
 #include "chrome/browser/profiles/profile_dependency_manager.h"
 #include "chrome/browser/ui/extensions/shell_window.h"
 #include "chrome/common/extensions/extension.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/web_contents.h"
 
+namespace extensions {
+
 ShellWindowRegistry::ShellWindowRegistry() {}
 
 ShellWindowRegistry::~ShellWindowRegistry() {}
 
 // static
 ShellWindowRegistry* ShellWindowRegistry::Get(Profile* profile) {
   return Factory::GetForProfile(profile);
 }
 
 void ShellWindowRegistry::AddShellWindow(ShellWindow* shell_window) {
@@ skipping 74 matching lines @@
   return new ShellWindowRegistry();
 }
 
 bool ShellWindowRegistry::Factory::ServiceIsCreatedWithProfile() {
   return true;
 }
 
 bool ShellWindowRegistry::Factory::ServiceIsNULLWhileTesting() {
   return false;
 }
+
+}  // namespace extensions