Add metrics for DHCP WPAD feature.

net/base/net_errors.h

 // Copyright (c) 2011 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_BASE_NET_ERRORS_H__
 #define NET_BASE_NET_ERRORS_H__
 #pragma once
 
+#include <vector>
+
 #include "base/basictypes.h"
 
 namespace net {
 
 // Error domain of the net module's error codes.
 extern const char kErrorDomain[];
 
 // Error values are negative.
 enum Error {
   // No error.
@@ skipping 13 matching lines @@
 // Returns true if |error| is a certificate error code.
 inline bool IsCertificateError(int error) {
   // Certificate errors are negative integers from net::ERR_CERT_BEGIN
   // (inclusive) to net::ERR_CERT_END (exclusive) in *decreasing* order.
   return error <= ERR_CERT_BEGIN && error > ERR_CERT_END;
 }
 
 // Map system error code to Error.
 Error MapSystemError(int os_error);
 
+// Returns a list of all the possible net error codes (not counting OK). This
+// is intended for use with UMA histograms that are reporting the result of
+// an action that is represented as a net error code.
+//
+// Note that the error codes are all positive (since histograms expect positive
+// sample values).
+std::vector<int> GetAllErrorCodesForUma();
+
 }  // namespace net
 
 #endif  // NET_BASE_NET_ERRORS_H__