Close SSLClientSocketOpenSSL cleanly if the transport was closed.

net/socket/ssl_client_socket_openssl.cc

Index: net/socket/ssl_client_socket_openssl.cc
diff --git a/net/socket/ssl_client_socket_openssl.cc b/net/socket/ssl_client_socket_openssl.cc
index 04be9881e170f4ca6289ee17f15c1e99642c4ebf..953f3363806cd25c7977b318804154fa6c49eef5 100644
--- a/net/socket/ssl_client_socket_openssl.cc
+++ b/net/socket/ssl_client_socket_openssl.cc
@@ -1363,6 +1363,15 @@ int SSLClientSocketOpenSSL::DoPayloadRead() {
     } else if (*next_result < 0) {
       int err = SSL_get_error(ssl_, *next_result);
       *next_result = MapOpenSSLError(err, err_tracer);
+
+      // Many servers do not reliably send a close_notify alert when shutting
+      // down a connection, and instead terminate the TCP connection. This is
+      // reported as ERR_CONNECTION_CLOSED. Because of this, map the unclean
+      // shutdown to a graceful EOF, instead of treating it as an error as it
+      // should be.
+      if (*next_result == ERR_CONNECTION_CLOSED)
+        *next_result = 0;
+
       if (rv > 0 && *next_result == ERR_IO_PENDING) {
           // If at least some data was read from SSL_read(), do not treat
           // insufficient data as an error to return in the next call to