Remove #pragma once from chrome/browser/extensions

chrome/browser/extensions/api/declarative/test_rules_registry.h

 // 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.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_API_DECLARATIVE_TEST_RULES_REGISTRY_H__
 #define CHROME_BROWSER_EXTENSIONS_API_DECLARATIVE_TEST_RULES_REGISTRY_H__
-#pragma once
 
 #include "chrome/browser/extensions/api/declarative/rules_registry_with_cache.h"
 
 namespace extensions {
 
 // This is a trivial test RulesRegistry that can only store and retrieve rules.
 class TestRulesRegistry : public RulesRegistryWithCache {
  public:
   TestRulesRegistry();
 
@@ skipping 20 matching lines @@
  private:
   // The string that gets returned by the implementation functions of
   // RulesRegistryWithCache. Defaults to "".
   std::string result_;
   content::BrowserThread::ID owner_thread_;
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_DECLARATIVE_TEST_RULES_REGISTRY_H__