Record the offscreen playing duration of autoplaying muted videos

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 75f16fdd33e2dc9286685a4235553e439a553fba..5a1ea1d4bb0461c4d3e3f4e23265c5f2cb928285 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -23299,6 +23299,17 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <summary>Records the autoplay source of muted videos.</summary>
 </histogram>
 
+<histogram name="Media.Video.Autoplay.Muted.Attribute.OffscreenDuration"
+    units="ms">
+  <owner>avayvod@chromium.org</owner>
+  <owner>mlamouri@chromium.org</owner>
+  <owner>zqzhang@chromium.org</owner>
+  <summary>
+    Records the offscreen playing duration of a muted video autoplaying from
+    autoplay attribute.
+  </summary>
+</histogram>
+
 <histogram name="Media.Video.Autoplay.Muted.PlayMethod.BecomesVisible"
     enum="Boolean">
   <owner>avayvod@chromium.org</owner>
@@ -23313,6 +23324,17 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="Media.Video.Autoplay.Muted.PlayMethod.OffscreenDuration"
+    units="ms">
+  <owner>avayvod@chromium.org</owner>
+  <owner>mlamouri@chromium.org</owner>
+  <owner>zqzhang@chromium.org</owner>
+  <summary>
+    Records the offscreen playing duration of a muted video autoplaying from
+    play() method.
+  </summary>
+</histogram>
+
 <histogram name="Media.Video.Autoplay.Muted.UnmuteAction" enum="BooleanSuccess">
   <owner>avayvod@chromium.org</owner>
   <owner>mlamouri@chromium.org</owner>