Track network stack error codes from UMA and UKM

components/metrics/metrics_log_uploader.h

 // Copyright 2014 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 COMPONENTS_METRICS_METRICS_LOG_UPLOADER_H_
 #define COMPONENTS_METRICS_METRICS_LOG_UPLOADER_H_
 
 #include <string>
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/strings/string_piece.h"
 
 namespace metrics {
 
 // MetricsLogUploader is an abstract base class for uploading UMA logs on behalf
 // of MetricsService.
 class MetricsLogUploader {
  public:
+  // Type for OnUploadComplete callbacks.  These callbacks will receive two
+  // parameters: A response code and an net error code.
+  typedef base::Callback<void(int, int)> UploadCallback;
+
   // Possible service types. This should correspond to a type from
   // DataUseUserData.
   enum MetricServiceType {
     UMA,
     UKM,
   };
 
   virtual ~MetricsLogUploader() {}
 
   // Uploads a log with the specified |compressed_log_data| and |log_hash|.
   // |log_hash| is expected to be the hex-encoded SHA1 hash of the log data
   // before compression.
   virtual void UploadLog(const std::string& compressed_log_data,
                          const std::string& log_hash) = 0;
 };
 
 }  // namespace metrics
 
 #endif  // COMPONENTS_METRICS_METRICS_LOG_UPLOADER_H_