Deprecating AutoplayExperimentHelper

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 9c0944a4ab52b56c33cb2128c0f33141f63d93bb..09f22a5ebfc3a5b33eb8283259a03897c0fab64c 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -4192,6 +4192,10 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 </histogram>
 
 <histogram name="Blink.MediaElement.Autoplay" enum="MediaElementAutoPlay">
+  <obsolete>
+    Deprecated 11/2016 in Issue 666370 with the deprecation of Autoplay
+    experiment.
+  </obsolete>
   <owner>oysteine@chromium.org</owner>
   <summary>
     Records user observation and interaction with Media HTML elements that
@@ -93564,6 +93568,10 @@ value.
 </enum>
 
 <enum name="MediaElementAutoPlay" type="int">
+  <obsolete>
+    Deprecated 11/2016 in Issue 666370 with the deprecation of Autoplay
+    experiment.
+  </obsolete>
   <int value="0" label="Media element with autoplay seen"/>
   <int value="1"
       label="Autoplay enabled and user stopped media play at any point"/>