Remove the deprecated cipher fallback.

net/http/http_network_transaction.cc

Index: net/http/http_network_transaction.cc
diff --git a/net/http/http_network_transaction.cc b/net/http/http_network_transaction.cc
index bc9666875110a56b522c617bd75b584e95708359..cc5e02efde4858667fe061160a720988fde25009 100644
--- a/net/http/http_network_transaction.cc
+++ b/net/http/http_network_transaction.cc
@@ -70,22 +70,6 @@
 
 namespace net {
 
-namespace {
-
-std::unique_ptr<base::Value> NetLogSSLCipherFallbackCallback(
-    const GURL* url,
-    int net_error,
-    NetLogCaptureMode /* capture_mode */) {
-  std::unique_ptr<base::DictionaryValue> dict(new base::DictionaryValue());
-  dict->SetString("host_and_port", GetHostAndPort(*url));
-  dict->SetInteger("net_error", net_error);
-  return std::move(dict);
-}
-
-}  // namespace
-
-//-----------------------------------------------------------------------------
-
 HttpNetworkTransaction::HttpNetworkTransaction(RequestPriority priority,
                                                HttpNetworkSession* session)
     : pending_auth_target_(HttpAuth::AUTH_NONE),
@@ -881,9 +865,6 @@ int HttpNetworkTransaction::DoCreateStreamComplete(int result) {
   if (result != ERR_HTTPS_PROXY_TUNNEL_RESPONSE)
     CopyConnectionAttemptsFromStreamRequest();
 
-  if (request_->url.SchemeIsCryptographic())
-    RecordSSLFallbackMetrics(result);
-
   if (result == OK) {
     next_state_ = STATE_INIT_STREAM;
     DCHECK(stream_.get());
@@ -1512,22 +1493,6 @@ void HttpNetworkTransaction::HandleClientAuthError(int error) {
 int HttpNetworkTransaction::HandleSSLHandshakeError(int error) {
   DCHECK(request_);
   HandleClientAuthError(error);
-
-  // Accept deprecated cipher suites, but only on a fallback. This makes UMA
-  // reflect servers require a deprecated cipher rather than merely prefer
-  // it. This, however, has no security benefit until the ciphers are actually
-  // removed.
-  if (!server_ssl_config_.deprecated_cipher_suites_enabled &&
-      (error == ERR_SSL_VERSION_OR_CIPHER_MISMATCH ||
-       error == ERR_CONNECTION_CLOSED || error == ERR_CONNECTION_RESET)) {
-    net_log_.AddEvent(
-        NetLogEventType::SSL_CIPHER_FALLBACK,
-        base::Bind(&NetLogSSLCipherFallbackCallback, &request_->url, error));
-    server_ssl_config_.deprecated_cipher_suites_enabled = true;
-    ResetConnectionAndRequestForResend();
-    return OK;
-  }
-
   return error;
 }
 
@@ -1641,14 +1606,6 @@ void HttpNetworkTransaction::CacheNetErrorDetailsAndResetStream() {
   stream_.reset();
 }
 
-void HttpNetworkTransaction::RecordSSLFallbackMetrics(int result) {
-  if (result != OK)
-    return;
-
-  UMA_HISTOGRAM_BOOLEAN("Net.ConnectionUsedSSLDeprecatedCipherFallback2",
-                        server_ssl_config_.deprecated_cipher_suites_enabled);
-}
-
 HttpResponseHeaders* HttpNetworkTransaction::GetResponseHeaders() const {
   return response_.headers.get();
 }