Chromoting is planning to bump up the iOS deployment target to 10.0
before but is blocked by WebRTC because it uses deprecated OSAtomic*
APIs.
This CL replaces the platform specific Atomic32 implementation and uses
C++11's std::atomic instead.
Bug: webrtc:8413
Change-Id: Icbd29bb92eec60066589bbabf53e0d50df2f9b0d
Reviewed-on: https://webrtc-review.googlesource.com/12740
Commit-Queue: Yuwei Huang <yuweih@google.com>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Reviewed-by: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#20376}
