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 03c38b4031ba17ab8655eac85b1f76ab066caf01..223b242604ef1bc844fe9ff424a2be473a76155b 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -10478,6 +10478,17 @@ 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>
@@ -38156,6 +38167,11 @@ 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"/>