Remove #pragma once from chrome/browser/extensions

chrome/browser/extensions/api/dns/host_resolver_wrapper.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_DNS_HOST_RESOLVER_WRAPPER_H_
 #define CHROME_BROWSER_EXTENSIONS_API_DNS_HOST_RESOLVER_WRAPPER_H_
-#pragma once
 
 #include "base/memory/singleton.h"
 #include "net/base/host_resolver.h"
 
 namespace extensions {
 
 // Used for testing. In production code, this class does nothing interesting.
 // This class is a singleton that holds a pointer to a mock HostResolver, or
 // else to NULL. API classes that need to resolve hostnames ask this class for
 // the correct HostResolver to use, passing in the one that they want to use,
@@ skipping 20 matching lines @@
   friend struct DefaultSingletonTraits<HostResolverWrapper>;
 
   net::HostResolver* resolver_;
 
   DISALLOW_COPY_AND_ASSIGN(HostResolverWrapper);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_DNS_HOST_RESOLVER_WRAPPER_H_