Disable inclusion of x509_certificate_model.h on unsupported platforms.

chrome/common/net/x509_certificate_model.h

 // Copyright (c) 2011 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 CHROME_COMMON_NET_X509_CERTIFICATE_MODEL_H_
 #define CHROME_COMMON_NET_X509_CERTIFICATE_MODEL_H_
 
+#if !defined(USE_NSS_CERTS) && !defined(USE_OPENSSL_CERTS)
+#error "This file must be built with either USE_NSS_CERTS or USE_OPENSSL_CERTS."
+#else
+
 #include <stddef.h>
 
 #include "net/cert/cert_type.h"
 #include "net/cert/x509_certificate.h"
 
 // This namespace defines a set of functions to be used in UI-related bits of
 // X509 certificates. It decouples the UI from the underlying crypto library
 // (currently NSS or OpenSSL - in development).
 // This is currently only used by linux, as mac / windows use their own native
 // certificate viewers and crypto libraries.
@@ skipping 99 matching lines @@
 
 #if defined(USE_NSS_CERTS)
 // Format a buffer as a space separated string, with 16 bytes on each line.
 // |data_length| is the length in bits.
 std::string ProcessRawBits(const unsigned char* data,
                            size_t data_length);
 #endif  // USE_NSS_CERTS
 
 }  // namespace x509_certificate_model
 
+#endif  // !defined(USE_NSS_CERTS) && !defined(USE_OPENSSL_CERTS)
+
 #endif  // CHROME_COMMON_NET_X509_CERTIFICATE_MODEL_H_