Reporting: Add histograms.

net/reporting/reporting_header_parser.h

 // Copyright 2017 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 NET_REPORTING_REPORTING_HEADER_PARSER_H_
 #define NET_REPORTING_REPORTING_HEADER_PARSER_H_
 
 #include <string>
 
 #include "base/macros.h"
 #include "net/base/net_export.h"
 
 class GURL;
 
 namespace net {
 
 class ReportingContext;
 
 class NET_EXPORT ReportingHeaderParser {
  public:
+  static void RecordHeaderDiscardedForNoReportingService();
+  static void RecordHeaderDiscardedForInvalidSSLInfo();
+  static void RecordHeaderDiscardedForCertStatusError();
+
   static void ParseHeader(ReportingContext* context,
                           const GURL& url,
                           const std::string& json_value);
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(ReportingHeaderParser);
 };
 
 }  // namespace net
 
 #endif  // NET_REPORTING_REPORTING_HEADER_PARSER_H_