Port 0794c3c9

Original commit message:
    As required by the spec, the second return value now returns success
    also for the range between 0 and -1 where the conversion results in 0.

R=ahaas@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=

Review URL: https://codereview.chromium.org/1538893002

Cr-Commit-Position: refs/heads/master@{#32972}