The pitch gain type in ComputePitchGainThreshold() is wrong
(size_t instead of float).
The pitch period is an unsigned integer type, but it is safer to
switch to a signed type and add checks on the sign.
Bug: webrtc:9076
Change-Id: If69d182071edab9750a320f0fbfac24aa8052ee0
Reviewed-on: https://webrtc-review.googlesource.com/c/117302
Reviewed-by: Alex Loiko <aleloi@webrtc.org>
Commit-Queue: Alessio Bazzica <alessiob@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#26259}
c25fa89e9e