It's more readable than the construction
Vector<T>(buffer, arraysize(buffer)).
All those places are now replaced by ArrayVector(buffer).

R=titzer@chromium.org, jarin@chromium.org, rossberg@chromium.org

Review-Url: https://codereview.chromium.org/1916393002
Cr-Commit-Position: refs/heads/master@{#35843}