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 3350b3a028b5037d7f9e254d8b2a9316331337c4..9c608827ab0c2879e4dc8cefcb07ed53fede2e48 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -23209,6 +23209,17 @@ 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>
@@ -23223,6 +23234,17 @@ 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>