Remove #pragma once from chrome/browser/policy

chrome/browser/policy/enterprise_metrics.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_ENTERPRISE_METRICS_H_
 #define CHROME_BROWSER_POLICY_ENTERPRISE_METRICS_H_
-#pragma once
 
 namespace policy {
 
 // Metrics collected for enterprise events.
 
 // Events related to fetching, saving and loading DM server tokens.
 // These metrics are collected both for device and user tokens.
 enum MetricToken {
   // A cached token was successfully loaded from disk.
   kMetricTokenLoadSucceeded,
@@ skipping 142 matching lines @@
 // Names for the UMA counters. They are shared from here since the events
 // from the same enum above can be triggered in different files, and must use
 // the same UMA histogram name.
 extern const char* kMetricToken;
 extern const char* kMetricPolicy;
 extern const char* kMetricEnrollment;
 
 }  // namespace policy
 
 #endif  // CHROME_BROWSER_POLICY_ENTERPRISE_METRICS_H_