Fix harmony-sharedarraybuffer implementation.
Fix harmony-sharedarraybuffer implementation.

NOTREECHECKS=true
NOTRY=true
TBR=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/1161553002

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#28609}

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