Distinguish between SCT invalidity reasons in UMA

net/cert/ct_sct_to_string.cc

Index: net/cert/ct_sct_to_string.cc
diff --git a/net/cert/ct_sct_to_string.cc b/net/cert/ct_sct_to_string.cc
index f3912a828623240199ee30e628887d997a746aff..2515707cdce6a3e33a70af8d6a4267e423247d35 100644
--- a/net/cert/ct_sct_to_string.cc
+++ b/net/cert/ct_sct_to_string.cc
@@ -62,12 +62,14 @@ 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_INVALID_TIMESTAMP:
+      return "Invalid timestamp";
     case SCT_STATUS_MAX:

[eroman, 2016/08/15 19:20:22]

See earlier comment -- we can remove handling of MAX unless there is a good
reason to have it in the code.

[Eran Messeri, 2016/08/16 14:17:18]

See my response above - it is a bit of a nuisance that the enum is used directly
for a histogram and so has this _MAX value. But that seems like a common
pattern:
https://cs.chromium.org/chromium/src/base/metrics/histogram_macros.h?q=UMA_HI...

       NOTREACHED();
   }