We get some alerts about the current metric with "no response" bucket being more prevalent under Enabled_NoDelay group of UMAUploadScheduler: 

https://uma.googleplex.com/variations?sid=0373829b6a2ae60e9f68d09e4259b7eb

"no response" is actually when we get an error from the network stack. So it would be good to understand these with a new histogram as we have for variations.

Steve is this something you want to look at?

Sure, I can add this.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/035ec7fb1af183cb9a902541b273208ddb6931ab

commit 035ec7fb1af183cb9a902541b273208ddb6931ab
Author: holte <holte@chromium.org>
Date: Tue Apr 04 20:16:59 2017

Track network stack error codes from UMA and UKM

BUG= 695538 

Review-Url: https://codereview.chromium.org/2774503002
Cr-Commit-Position: refs/heads/master@{#461811}

[modify] https://crrev.com/035ec7fb1af183cb9a902541b273208ddb6931ab/android_webview/native/aw_metrics_log_uploader.cc
[modify] https://crrev.com/035ec7fb1af183cb9a902541b273208ddb6931ab/android_webview/native/aw_metrics_log_uploader.h
[modify] https://crrev.com/035ec7fb1af183cb9a902541b273208ddb6931ab/android_webview/native/aw_metrics_service_client_impl.cc
[modify] https://crrev.com/035ec7fb1af183cb9a902541b273208ddb6931ab/android_webview/native/aw_metrics_service_client_impl.h
[modify] https://crrev.com/035ec7fb1af183cb9a902541b273208ddb6931ab/chrome/browser/metrics/chrome_metrics_service_client.cc
[modify] https://crrev.com/035ec7fb1af183cb9a902541b273208ddb6931ab/chrome/browser/metrics/chrome_metrics_service_client.h
[modify] https://crrev.com/035ec7fb1af183cb9a902541b273208ddb6931ab/chromecast/browser/metrics/cast_metrics_service_client.cc
[modify] https://crrev.com/035ec7fb1af183cb9a902541b273208ddb6931ab/chromecast/browser/metrics/cast_metrics_service_client.h
[modify] https://crrev.com/035ec7fb1af183cb9a902541b273208ddb6931ab/components/metrics/metrics_log_uploader.h
[modify] https://crrev.com/035ec7fb1af183cb9a902541b273208ddb6931ab/components/metrics/metrics_reporting_service.cc
[modify] https://crrev.com/035ec7fb1af183cb9a902541b273208ddb6931ab/components/metrics/metrics_reporting_service.h
[modify] https://crrev.com/035ec7fb1af183cb9a902541b273208ddb6931ab/components/metrics/metrics_service_client.h
[modify] https://crrev.com/035ec7fb1af183cb9a902541b273208ddb6931ab/components/metrics/net/net_metrics_log_uploader.cc
[modify] https://crrev.com/035ec7fb1af183cb9a902541b273208ddb6931ab/components/metrics/net/net_metrics_log_uploader.h
[modify] https://crrev.com/035ec7fb1af183cb9a902541b273208ddb6931ab/components/metrics/net/net_metrics_log_uploader_unittest.cc
[modify] https://crrev.com/035ec7fb1af183cb9a902541b273208ddb6931ab/components/metrics/reporting_service.cc
[modify] https://crrev.com/035ec7fb1af183cb9a902541b273208ddb6931ab/components/metrics/reporting_service.h
[modify] https://crrev.com/035ec7fb1af183cb9a902541b273208ddb6931ab/components/metrics/test_metrics_log_uploader.cc
[modify] https://crrev.com/035ec7fb1af183cb9a902541b273208ddb6931ab/components/metrics/test_metrics_log_uploader.h
[modify] https://crrev.com/035ec7fb1af183cb9a902541b273208ddb6931ab/components/metrics/test_metrics_service_client.cc
[modify] https://crrev.com/035ec7fb1af183cb9a902541b273208ddb6931ab/components/metrics/test_metrics_service_client.h
[modify] https://crrev.com/035ec7fb1af183cb9a902541b273208ddb6931ab/components/ukm/ukm_reporting_service.cc
[modify] https://crrev.com/035ec7fb1af183cb9a902541b273208ddb6931ab/components/ukm/ukm_reporting_service.h
[modify] https://crrev.com/035ec7fb1af183cb9a902541b273208ddb6931ab/ios/chrome/browser/metrics/ios_chrome_metrics_service_client.h
[modify] https://crrev.com/035ec7fb1af183cb9a902541b273208ddb6931ab/ios/chrome/browser/metrics/ios_chrome_metrics_service_client.mm
[modify] https://crrev.com/035ec7fb1af183cb9a902541b273208ddb6931ab/ios/chrome/today_extension/today_metrics_logger.mm
[modify] https://crrev.com/035ec7fb1af183cb9a902541b273208ddb6931ab/tools/metrics/histograms/histograms.xml