Port 0d595bb0

Original commit message:
    It's fine to only have the runtime call here, as it's only used in the
    debug mirror.

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

Review URL: https://codereview.chromium.org/1707683002

Cr-Commit-Position: refs/heads/master@{#34085}