The wire bytes are currently stored as {SeqOneByteString} on the JS
heap. In order to make the {NativeModule} isolate independent, and to
ensure fast access to the wire bytes, they should move to the native
heap.

R=titzer@chromium.org

Bug: chromium:854794, v8:7868, v8:7424
Cq-Include-Trybots: luci.chromium.try:linux_chromium_rel_ng
Change-Id: I36811ec87f780c5b1f6863cd6de89a165aa0b7d5
Reviewed-on: https://chromium-review.googlesource.com/1108208
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Ben Titzer <titzer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53977}