Track network stack error codes from UMA and UKM

components/metrics/metrics_reporting_service.cc

 // 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.
 
 // ReportingService specialized to report UMA metrics.
 
 #include "components/metrics/metrics_reporting_service.h"
 
 #include "base/bind.h"
 #include "base/callback.h"
@@ skipping 78 matching lines @@
                         upload_canceled);
 }
 
 void MetricsReportingService::LogResponseCode(int response_code) {
   // Log a histogram to track response success vs. failure rates.
   UMA_HISTOGRAM_ENUMERATION("UMA.UploadResponseStatus.Protobuf",
                             ResponseCodeToStatus(response_code),
                             NUM_RESPONSE_STATUSES);
 }
 
+void MetricsReportingService::LogErrorCode(int error_code) {
+  UMA_HISTOGRAM_SPARSE_SLOWLY("UMA.FailedUploadErrorCode", -error_code);

[Alexei Svitkine (slow), 2017/03/23 15:23:42]

I think error and response code should be logged in the same histogram, like we
do for Variations.SeedFetchResponseOrErrorCode.

We can deprecate UMA.UploadResponseStatus.Protobuf at the same time.

[Steven Holte, 2017/03/23 20:38:07]

Done.

+}
+
 void MetricsReportingService::LogSuccess(size_t log_size) {
   UMA_HISTOGRAM_COUNTS_10000("UMA.LogSize.OnSuccess", log_size / 1024);
 }
 
 void MetricsReportingService::LogLargeRejection(size_t log_size) {
   UMA_HISTOGRAM_COUNTS_1M("UMA.Large Rejected Log was Discarded",
                           static_cast<int>(log_size));
 }
 
 }  // namespace metrics