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 f7fd8937c039f19f0327adf824671dab93cf2849..ab92e9ae51d18804e661d7d5236e003f4f61768a 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -46290,6 +46290,23 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="Permissions.AutoBlocker.EmbargoPromptSuppression"
+    enum="PermissionEmbargoStatus">
+  <owner>dominickn@chromium.org</owner>
+  <owner>kcarattini@chromium.org</owner>
+  <summary>
+    For every permission request that would show a prompt to the user, this
+    metric tracks whether the request is suppressed by embargo (and the source
+    of that embargo), or whether there is no embargo and the prompt is shown.
+    This is the proportion of permission prompts that the user would have seen
+    that have been blocked due to embargo.
+
+    If the (origin, permission) pair was previously placed under embargo, no
+    prompt is displayed and the reason for embargo is recorded. Otherwise, the
+    prompt is shown and a no embargo reason is recorded.

[Ilya Sherman, 2017/02/23 07:58:52]

Hmm, I'm a bit confused: Here you say that nothing is recorded if there was no
embargo; but above, you say that the metric tracks *whether* the request is
suppressed, which implies that there's a way to tell how often the permission is
*not* embargoed.  These two statements seem to contradict each other.  What am I
missing?

[dominickn, 2017/02/23 08:05:49]

A "no embargo" reason is recorded, not "no embargo reason is recorded". Does
that clarify?

[Ilya Sherman, 2017/02/23 08:08:41]

Ah, yes, I misread that sentence.  Makes sense now, thanks!

+  </summary>
+</histogram>
+
 <histogram name="Permissions.AutoBlocker.EmbargoStatus"
     enum="PermissionEmbargoStatus">
   <owner>dominickn@chromium.org</owner>