Update NSS to 3.16.4. Updated to Chromium's copy of NSS at revision 291806

dart/runtime/bin/net/nss_memio.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.
 // Written in NSPR style to also be suitable for adding to the NSS demo suite
 
 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 // This file is a modified copy of Chromium's src/net/base/nss_memio.h.
 // char* has been changed to uint8_t* everywhere, and C++ casts are used.
-// Revision 257452 (this should agree with "nss_rev" in DEPS).
+// Revision 291806 (this should agree with "nss_rev" in DEPS).
 
 #ifndef BIN_NET_NSS_MEMIO_H_
 #define BIN_NET_NSS_MEMIO_H_
 
 #include <stddef.h>
 #include "vm/globals.h"
 
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ skipping 58 matching lines @@
  * If bytes_read is 0, causes EOF to be reported to
  * NSS after it reads the last byte from the circular buffer.
  * If bytes_read is < 0, it is treated as an NSPR error code.
  * See nspr/pr/src/md/unix/unix_errors.c for how to
  * map from Unix errors to NSPR error codes.
  * On EWOULDBLOCK or the equivalent, don't call this function.
  */
 void memio_PutReadResult(memio_Private *secret, int bytes_read);
 
 /* Ask memio what data it has to send to the network.
- * Returns up to two buffers of data by writing the positions and lengths into
- * |buf1|, |len1| and |buf2|, |len2|.
+ * If there was previous a write error, the NSPR error code is returned.
+ * Otherwise, it returns 0 and provides up to two buffers of data by
+ * writing the positions and lengths into |buf1|, |len1| and |buf2|, |len2|.
  */
-void memio_GetWriteParams(memio_Private *secret,
-                          const uint8_t **buf1, unsigned int *len1,
-                          const uint8_t **buf2, unsigned int *len2);
+int memio_GetWriteParams(memio_Private *secret,
+                         const uint8_t **buf1, unsigned int *len1,
+                         const uint8_t **buf2, unsigned int *len2);
 
 /* Tell memio how many bytes were sent to the network.
  * If bytes_written is < 0, it is treated as an NSPR error code.
  * See nspr/pr/src/md/unix/unix_errors.c for how to
  * map from Unix errors to NSPR error codes.
  * On EWOULDBLOCK or the equivalent, don't call this function.
  */
 void memio_PutWriteResult(memio_Private *secret, int bytes_written);
 
 #ifdef __cplusplus
 }
 #endif
 
 #endif  // BIN_NET_NSS_MEMIO_H_