This CL changes the updating of a loop index from using the modulus
operator to using a conditional, avoiding the divisions done in the
modulus operator which had a measurable impact on mpbile
platforms.
Additionally, there is a similar removal of another modulus operator, but the impact of that should be negligible.
BUG=webrtc:7666
Review-Url: https://codereview.webrtc.org/2882183004
Cr-Commit-Position: refs/heads/master@{#18168}
94f6fa0526