The functions "memcpy" and "memset" are defined in "string.h" which
was not included. Found this when compiling with g++ 5.4 on Ubuntu
Xenial.
Bug: None
Change-Id: Ife9a9ce2a168ecc24d983afcfc0a39784cbedf9f
Reviewed-on: https://webrtc-review.googlesource.com/54121
Reviewed-by: Gustaf Ullberg <gustaf@webrtc.org>
Commit-Queue: Gustaf Ullberg <gustaf@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#22043}