Roughly:
    GetIsolate(): -31
    handle(HeapObject): -6

TBR=verwaest@chromium.org

Bug: v8:7786
Change-Id: I3857f8c45f1f93c727d575d5f9244d9811949a7f
Reviewed-on: https://chromium-review.googlesource.com/1111838Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Dan Elphick <delphick@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53997}