Check X509Certificate::CreateFromHandle result.

net/cert/x509_certificate.h

 // Copyright (c) 2012 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.
 
 #ifndef NET_CERT_X509_CERTIFICATE_H_
 #define NET_CERT_X509_CERTIFICATE_H_
 
 #include <stddef.h>
 #include <string.h>
 
@@ skipping 109 matching lines @@
 
     // The Pickle contains the certificate and any certificates that were
     // stored in |intermediate_ca_certs_| at the time it was serialized.
     // The format is [int count], [data - this certificate],
     // [data - intermediate1], ... [data - intermediateN].
     // All certificates are stored in DER form.
     PICKLETYPE_CERTIFICATE_CHAIN_V3,
   };
 
   // Create an X509Certificate from a handle to the certificate object in the
-  // underlying crypto library.
+  // underlying crypto library. Returns NULL on failure to parse or extract
+  // data from the the certificate. Note that this does not guarantee the
+  // certificate is fully parsed and validated, only that the members of this
+  // class, such as subject, issuer, expiry times, and serial number, could be
+  // successfully initialized from the certificate.
   static scoped_refptr<X509Certificate> CreateFromHandle(
       OSCertHandle cert_handle,
       const OSCertHandles& intermediates);
 
   // Create an X509Certificate from a chain of DER encoded certificates. The
   // first certificate in the chain is the end-entity certificate to which a
   // handle is returned. The other certificates in the chain are intermediate
   // certificates.
   static scoped_refptr<X509Certificate> CreateFromDERCertChain(
       const std::vector<base::StringPiece>& der_certs);
@@ skipping 306 matching lines @@
   // Untrusted intermediate certificates associated with this certificate
   // that may be needed for chain building.
   OSCertHandles intermediate_ca_certs_;
 
   DISALLOW_COPY_AND_ASSIGN(X509Certificate);
 };
 
 }  // namespace net
 
 #endif  // NET_CERT_X509_CERTIFICATE_H_