Add owner for DOM Distiller quality histogram.

TBR=asvitkine@chromium.org
BUG=None

Review URL: https://codereview.chromium.org/475653002

Cr-Commit-Position: refs/heads/master@{#289620}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@289620 0039d316-1c4b-4281-b951-d872f2087c98

tools/metrics/histograms/histograms.xml

@@ -4998,7 +4998,7 @@ Therefore, the affected-histogram name has to have at least one dot in it.
 </histogram>
 
 <histogram name="DomDistiller.DistillationQuality" enum="BooleanSuccess">
-  <owner>Please list the metric's owners. Add more owner tags as needed.</owner>
+  <owner>nyquist@chromium.org</owner>
   <summary>
     Whether the perceived quality of the distillation of a web page was good.
   </summary>