GitLab

Pass Isolate* through to StringObject::New, String::Concat,
Value::ToString and StackTrace::GetFrame as the non-Isolate forms are
deprecated.

Change-Id: Ib064eb3beba9493ba67e679118a6369c22cb92cb
Reviewed-on: https://chromium-review.googlesource.com/1150030Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Devlin <rdevlin.cronin@chromium.org>
Commit-Queue: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#577964}