Worker: Fix wrong stack size calculation

Before this CL, stack size for worker threads is unexpectedly lowered than the
intended size (500KB) because a denominator sizeof(uint32_t*) in the calculation
is not correct. This should have been sizeof(uint32_t). This CL fixes it.

BUG=252492

Review-Url: https://codereview.chromium.org/2506583002
Cr-Commit-Position: refs/heads/master@{#432267}
1 file changed