Properly handle alerts from the peer in SSL_read.

net/ssl/openssl_ssl_util.h

Index: net/ssl/openssl_ssl_util.h
diff --git a/net/ssl/openssl_ssl_util.h b/net/ssl/openssl_ssl_util.h
index a0339fca18d59101a594090de55dc341dfb97756..051449996346ee6f01f6e3f8410415ddc8fddc1e 100644
--- a/net/ssl/openssl_ssl_util.h
+++ b/net/ssl/openssl_ssl_util.h
@@ -51,7 +51,8 @@ struct OpenSSLErrorInfo {
 // Converts an OpenSSL error code into a net error code, walking the OpenSSL
 // error stack if needed. If a value on the stack is used, the error code and
 // associated information are returned in |*out_error_info|. Otherwise its
-// fields are set to 0 and NULL.
+// fields are set to 0 and NULL. This function will never return OK, so
+// SSL_ERROR_ZERO_RETURN must be handled externally.
 //
 // Note that |tracer| is not currently used in the implementation, but is passed
 // in anyway as this ensures the caller will clear any residual codes left on