Add a DevTools warning for a missing subjectAltName

components/security_state_strings.grdp

Index: components/security_state_strings.grdp
diff --git a/components/security_state_strings.grdp b/components/security_state_strings.grdp
index a193d68acd303b307bdcddc9989eef798bc81568..d3580a9af31aaaf6b987fa190cacfac0aeb3149d 100644
--- a/components/security_state_strings.grdp
+++ b/components/security_state_strings.grdp
@@ -13,6 +13,12 @@
   <message name="IDS_SHA1_DESCRIPTION" desc="Description of a security problem where the site's certificate chain contains a SHA1 signature." translateable="false">
     The certificate chain for this site contains a certificate signed using SHA-1.
   </message>
+  <message name="IDS_SUBJECT_ALT_NAME_MISSING" desc="Summary phrase for a security problem where the site's certificate is missing a subjectAltName extension." translateable="false">
+    Subject Alternative Name Missing
+  </message>
+  <message name="IDS_SUBJECT_ALT_NAME_MISSING_DESCRIPTION" desc="Description of a security problem where the site's certificate is missing a subjectAltName extension." translateable="false">
+    The certificate for this site does not contain a Subject Alternative Name extension containing a domain name or IP address.
+  </message>
   <message name="IDS_CERTIFICATE_CHAIN_ERROR" desc="Summary phrase for a security problem with the site's certificate." translateable="false">
     Certificate Error
   </message>