Add workaround for type change in webrtc api.

As of cl https://codereview.webrtc.org/2781433002/ the max_pixel_count
type of rtc::VideoWinkWants will change from an Optional<int> to a plain
int. Until that CL has landed and been imported into Chrome, use a type
alias that will work with either.

BUG=webrtc:4172

Review-Url: https://codereview.chromium.org/2785683002
Cr-Commit-Position: refs/heads/master@{#460356}
1 file changed