[Blink>Media] Adding rappor metrics to record autoplay muted by attribute usage

tools/metrics/rappor/rappor.xml

Index: tools/metrics/rappor/rappor.xml
diff --git a/tools/metrics/rappor/rappor.xml b/tools/metrics/rappor/rappor.xml
index 500d02c195f2ac3762c4831e06a5a22792394f07..2e511d6b282ab98487f0ad8783234f73a74033e5 100644
--- a/tools/metrics/rappor/rappor.xml
+++ b/tools/metrics/rappor/rappor.xml
@@ -1334,6 +1334,28 @@ now we are only interested in H264, VP8 and VP9.
   </summary>
 </rappor-metric>
 
+<rappor-metric name="Media.Video.Autoplay.Muted.Attribute.ChildFrame"
+    type="ETLD_PLUS_ONE">
+  <owner>avayvod@chromium.org</owner>
+  <owner>mlamouri@chromium.org</owner>
+  <owner>zqzhang@chromium.org</owner>
+  <summary>
+    The eTLD+1 of the child frame URL that has an autoplay muted video by
+    attribute.
+  </summary>
+</rappor-metric>
+
+<rappor-metric name="Media.Video.Autoplay.Muted.Attribute.TopLevelFrame"
+    type="ETLD_PLUS_ONE">
+  <owner>avayvod@chromium.org</owner>
+  <owner>mlamouri@chromium.org</owner>
+  <owner>zqzhang@chromium.org</owner>
+  <summary>
+    The eTLD+1 of the top-level frame URL that has an autoplay muted video by
+    attribute in itself or one of its child frames.
+  </summary>
+</rappor-metric>
+
 <rappor-metric name="NTP.ExplicitUserAction.PageNavigation.NTPTileClick"
     type="UMA_RAPPOR_TYPE">
   <owner>knn@chromium.org</owner>