Track how often we would attempt to resolve non-'compliant' domain names.

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 2bb0c08e8bf28f407f7c5d54c7648401c91fb1f8..7ef61c793e97e69f5b56f0824b5635599da9d6fa 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -40028,6 +40028,18 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+Net.ValidAndCompliantDNSName
+<histogram name="Net.ValidAndCompliantDNSName" enum="Boolean">
+  <owner>palmer@chromium.org</owner>
+  <summary>
+    True if Net.ValidDNSName is true and if |net::IsCanonicalizedHostCompliant|
+    returns true. Used to see if we can deprecate and remove support for

[Peter Kasting, 2017/05/25 20:03:30]

Is this second sentence really accurate?  It sounds like it might be a
copy-and-paste and should have been something like "Used to see if
IsCanonicalizedHostCompliant() runs afoul of real websites."

[palmer, 2017/05/25 20:41:41]

Done!

+    arbitrary bytes in DNS names. This histogram is recorded when converting
+    dotted DNS names into DNS query form, in preparation for issuing a DNS
+    request.
+  </summary>
+</histogram>
+
 <histogram name="Net.ValidDNSName" enum="Boolean">
   <owner>palmer@chromium.org</owner>
   <summary>