Add UMA histogram to count hard revokes of user certificate error decisions.

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 231196dbec0872174bc4f12ea8d1d481d8f6a10c..412b48196426d9a88869e7756ce05697d83ac203 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -10309,6 +10309,17 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   </summary>
 </histogram>
 
+<histogram name="interstitial.ssl.did_user_revoke_decisions"
+    enum="BooleanRevoked">
+  <owner>jww@chromium.org</owner>
+  <summary>
+    Specifies when a user enters the page info menu whether or not the user
+    pressed the SSL decisions revoke button. This can only by done if the user
+    is in the &quot;Remember Certificate Error Decisions&quot; experiment. This
+    is logged when the page info UI is closed.
+  </summary>
+</histogram>
+
 <histogram name="interstitial.ssl.expiration_and_decision.nonoverridable"
     enum="SSLIsExpiredAndDecision">
   <owner>jww@chromium.org</owner>
@@ -37826,6 +37837,11 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   <int value="1" label="Reported"/>
 </enum>
 
+<enum name="BooleanRevoked" type="int">
+  <int value="0" label="Not revoked"/>
+  <int value="1" label="Revoked"/>
+</enum>
+
 <enum name="BooleanSelected" type="int">
   <int value="0" label="No selection"/>
   <int value="1" label="Selected"/>