Revert of purge nss files and dependencies

webrtc/base/opensslstreamadapter.cc

 /*
  *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 1023 matching lines @@
   if (stream->peer_certificate_digest_algorithm_.empty()) {
     return 0;
   }
   X509* cert = X509_STORE_CTX_get_current_cert(store);
   int depth = X509_STORE_CTX_get_error_depth(store);
 
   // For now We ignore the parent certificates and verify the leaf against
   // the digest.
   //
   // TODO(jiayl): Verify the chain is a proper chain and report the chain to
-  // |stream->peer_certificate_|.
+  // |stream->peer_certificate_|, like what NSS does.
   if (depth > 0) {
     LOG(LS_INFO) << "Ignored chained certificate at depth " << depth;
     return 1;
   }
 
   unsigned char digest[EVP_MAX_MD_SIZE];
   size_t digest_length;
   if (!OpenSSLCertificate::ComputeDigest(
            cert,
            stream->peer_certificate_digest_algorithm_,
@@ skipping 108 matching lines @@
 #endif
     }
   } else {
     return std::string();
   }
 }
 
 }  // namespace rtc
 
 #endif  // HAVE_OPENSSL_SSL_H