Track network stack error codes from UMA and UKM

tools/metrics/histograms/histograms.xml

Index: tools/metrics/histograms/histograms.xml
diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index 6826f2558c71fc6ddf9c13c1bb1f8333f91d183e..2c64f9d404feb73c49ed770cdda86ef54649cc0b 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -72915,6 +72915,16 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="UKM.LogUpload.ResponseOrErrorCode"
+    enum="CombinedHttpResponseAndNetErrorCode">
+  <owner>holte@chromium.org</owner>
+  <owner>rkaplow@chromium.org</owner>
+  <summary>
+    HTTP response codes and network error encountered by UKM when attempting to

[Alexei Svitkine (slow), 2017/03/23 20:41:58]

Nit: errors (plural)

[Steven Holte, 2017/03/23 21:08:52]

Done.

+    upload logs to the server.
+  </summary>
+</histogram>
+
 <histogram name="UKM.PersistentLogRecall.Status"
     enum="PersistedLogsLogReadStatus">
   <owner>holte@chromium.org</owner>
@@ -72955,6 +72965,9 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 </histogram>
 
 <histogram name="UKM.Upload.ResponseCode" enum="HttpResponseCode">
+  <obsolete>
+    Replaced by UKM.LogUpload.ResponseOrErrorCode
+  </obsolete>
   <owner>holte@chromium.org</owner>
   <owner>rkaplow@chromium.org</owner>
   <summary>
@@ -73453,6 +73466,16 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="UMA.LogUpload.ResponseOrErrorCode"
+    enum="CombinedHttpResponseAndNetErrorCode">
+  <owner>holte@chromium.org</owner>
+  <owner>asvitkine@chromium.org</owner>
+  <summary>
+    HTTP response codes and network error encountered by UMA when attempting to

[Alexei Svitkine (slow), 2017/03/23 20:41:58]

Nit: errors (plural)

[Steven Holte, 2017/03/23 21:08:53]

Done.

+    upload logs to the server.
+  </summary>
+</histogram>
+
 <histogram name="UMA.LowEntropySourceValue">
   <owner>asvitkine@chromium.org</owner>
   <summary>
@@ -73692,6 +73715,9 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 
 <histogram name="UMA.UploadResponseStatus.Protobuf"
     enum="UmaUploadResponseStatus">
+  <obsolete>
+    Replaced by UMA.LogUpload.ResponseOrErrorCode
+  </obsolete>
   <owner>asvitkine@chromium.org</owner>
   <summary>
     For each upload to the protocol buffer (v2) UMA server, log whether the