New SSL metric added: Likely From Same Domain

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 86071992c1731eab7bf35a0ae8a3aa691548f114..1b840ce5ef7d5455277ef2520b96f4bf14c0ae15 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -68276,6 +68276,13 @@ To add a new entry, add it with any value and run test to compute valid value.
   <int value="12" label="EXPIRED_RECENTLY: Cert expired within last 28 days.">
 
   </int>
+  <int value="13"
+      label="LIKELY_SAME_DOMAIN: Cert likely belongs to the same domain">
+    This case is recorded if the SSL error is CERT_COMMON_NAME_INVALID error and
+    the hostname in request URL has the same domain (effective TLD + 1 label) as
+    the common name or at least one of the subject alternative names in
+    certificate. This case is not recorded if the host name is not a known tld.
+  </int>
 </enum>
 
 <enum name="SSLErrorHandlerEvent" type="int">