FrameSet: Fix an integer overflow

crrev.com/1035755 introduced an integer overflow:
  (int * int) / int64_t
The type of the multiplication result is |int|, and can overflow.

This CL changes it like:
  ClampTo<int>((int * int64_t) / int64_t)

Bug: 1353277
Change-Id: Ib59d1a16762e139bf882a8619e344914339d535d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3836624
Auto-Submit: Kent Tamura <tkent@chromium.org>
Reviewed-by: Morten Stenshorne <mstensho@chromium.org>
Commit-Queue: Morten Stenshorne <mstensho@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1036498}