Serializer: reset typed array cell type.
Serializer: reset typed array cell type.

R=mvstanton@chromium.org
BUG=chromium:449937
LOG=N

Review URL: https://codereview.chromium.org/861583002

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#26133}

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