Fix a benign off-by-one error of kNumSerials in IsBlacklisted.

net/base/x509_certificate.cc

Index: net/base/x509_certificate.cc
===================================================================
--- net/base/x509_certificate.cc	(revision 99223)
+++ net/base/x509_certificate.cc	(working copy)
@@ -641,7 +641,7 @@
 }
 
 bool X509Certificate::IsBlacklisted() const {
-  static const unsigned kNumSerials = 257;
+  static const unsigned kNumSerials = 256;

[wtc, 2011/09/01 21:15:19]

I verified that 256 is correct because 255 results in a
compilation error (too many initializers).

I believe this off-by-one error is benign because the
last entry should be initialized to all zeros by the compiler.  That is an
unlikely serial number.

The only problem with the off-by-one error is the
histogram entry for the special-case certificate
will be off by one.

   static const unsigned kSerialBytes = 16;
   static const uint8 kSerials[kNumSerials][kSerialBytes] = {
     // Not a real certificate. For testing only.
@@ -947,8 +947,9 @@
   if (serial_number_.size() == sizeof(kDigiNotarLeadingZero) &&
       memcmp(serial_number_.data(), kDigiNotarLeadingZero,
              sizeof(kDigiNotarLeadingZero)) == 0) {
-        UMA_HISTOGRAM_ENUMERATION("Net.SSLCertBlacklisted", kNumSerials, kNumSerials + 1);
-        return true;
+    UMA_HISTOGRAM_ENUMERATION("Net.SSLCertBlacklisted", kNumSerials,
+                              kNumSerials + 1);
+    return true;
   }
 
   return false;