Also changed string.js and math.js to adapt this change.

R=jkummerow@chromium.org

Committed: https://crrev.com/e25058b0b7b9831162579564fc8935d568c1ecdd
Cr-Commit-Position: refs/heads/master@{#28521}

Review URL: https://codereview.chromium.org/1143993003

Cr-Commit-Position: refs/heads/master@{#28533}