Remove #pragma once from chrome/browser/policy

chrome/browser/policy/policy_loader_win.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_POLICY_POLICY_LOADER_WIN_H_
 #define CHROME_BROWSER_POLICY_POLICY_LOADER_WIN_H_
-#pragma once
 
 #include "base/synchronization/waitable_event.h"
 #include "base/win/object_watcher.h"
 #include "chrome/browser/policy/async_policy_loader.h"
 
 namespace policy {
 
 struct PolicyDefinitionList;
 class PolicyMap;
 
@@ skipping 54 matching lines @@
   // Key in a JSON schema that indicates the default schema for object
   // properties.
   extern const char kAdditionalProperties[];
   // Key in a JSON schema that indicates the expected type of list items.
   extern const char kItems[];
 }  // namespace registry_constants
 
 }  // namespace policy
 
 #endif  // CHROME_BROWSER_POLICY_POLICY_LOADER_WIN_H_