Distinguish between SCT invalidity reasons in UMA

net/cert/ct_sct_to_string.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/cert/ct_sct_to_string.h"
 
 namespace net {
 
 namespace ct {
 
@@ skipping 44 matching lines @@
     case SignedCertificateTimestamp::SCT_ORIGIN_MAX:
       NOTREACHED();
   }
   return "Unknown";
 }
 
 const std::string StatusToString(SCTVerifyStatus status) {
   switch (status) {
     case SCT_STATUS_LOG_UNKNOWN:
       return "From unknown log";
-    case SCT_STATUS_INVALID:
-      return "Invalid";
+    case SCT_STATUS_INVALID_SIGNATURE:
+      return "Invalid signature";
     case SCT_STATUS_OK:
       return "Verified";
     case SCT_STATUS_NONE:
       return "None";
-    case SCT_STATUS_MAX:
-      NOTREACHED();
+    case SCT_STATUS_INVALID_TIMESTAMP:
+      return "Invalid timestamp";
   }
   return "Unknown";
 }
 
 }  // namespace ct
 
 }  // namespace net