Merge third_party/usrsctp/usrsctplib from https://chromium.googlesource.com/external/usrsctplib.git at d5685d4cc67d1fba57b7cb0024fc9065971e5ac1

This commit was generated by merge_from_chromium.py.

Change-Id: I12fa2c1bcb9e48a54975f5346a7fcebd63ff1d10