Fix dumping of counters in d8.
Fix dumping of counters in d8.

R=hpayer@chromium.org

Review URL: https://codereview.chromium.org/721193002

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#25334}

UniversalFuture/moosh,UniversalFuture/moosh,UniversalFuture/moosh,UniversalFuture/moosh