Adding Rappor metrics for disabling cross-origin autoplay with sound experiment

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 f8a23ed82c173273afc1d6f11801a835b471e513..53f50208d61a7aa85dbe06d568faa3c14a5ef8b0 100644
--- a/tools/metrics/rappor/rappor.xml
+++ b/tools/metrics/rappor/rappor.xml
@@ -994,6 +994,73 @@ components/rappor/rappor_parameters.h.
   </summary>
 </rappor-metric>
 
+<rappor-metric name="Media.Autoplay.CrossOrigin.Allowed.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 a cross-origin iframe URL containing media that was allowed to
+    autoplay.
+  </summary>
+</rappor-metric>
+
+<rappor-metric name="Media.Autoplay.CrossOrigin.Allowed.ChildFrame"

[mlamouri (slow - plz ping), 2016/12/08 17:17:06]

s/Allowed/Blocked/

[Zhiqiang Zhang (Slow), 2016/12/08 17:35:29]

Done.

+    type="ETLD_PLUS_ONE">
+  <owner>avayvod@chromium.org</owner>
+  <owner>mlamouri@chromium.org</owner>
+  <owner>zqzhang@chromium.org</owner>
+  <summary>
+    The eTLD+1 of a cross-origin iframe URL containing media that was blocked to
+    autoplay.
+  </summary>
+</rappor-metric>
+
+<rappor-metric name="Media.Autoplay.CrossOrigin.Allowed.ChildFrame"

[mlamouri (slow - plz ping), 2016/12/08 17:17:06]

s/Allowed/PlayedWithGesture/

... same for the TopLevelFrame ones below

[Zhiqiang Zhang (Slow), 2016/12/08 17:35:29]

Done.

+    type="ETLD_PLUS_ONE">
+  <owner>avayvod@chromium.org</owner>
+  <owner>mlamouri@chromium.org</owner>
+  <owner>zqzhang@chromium.org</owner>
+  <summary>
+    The eTLD+1 of a cross-origin iframe URL containing media that was blocked to
+    autoplay but the user plays the media by gesture at some point.
+  </summary>
+</rappor-metric>
+
+<rappor-metric name="Media.Autoplay.CrossOrigin.Allowed.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 a cross-origin iframe
+    containing media that was allowed to autoplay.
+  </summary>
+</rappor-metric>
+
+<rappor-metric name="Media.Autoplay.CrossOrigin.Allowed.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 a cross-origin iframe
+    containing media that was blocked to autoplay.
+  </summary>
+</rappor-metric>
+
+<rappor-metric name="Media.Autoplay.CrossOrigin.Allowed.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 a cross-origin iframe
+    containing media that was allowed to autoplay but the user plays the media
+    by gesture at some point.
+  </summary>
+</rappor-metric>
+
 <rappor-metric name="Media.OriginUrl.EME" type="ETLD_PLUS_ONE">
   <owner>xhwang@chromium.org</owner>
   <summary>