A window is a Blink concept. This API marks the context as backing
a detached window. This doesn't necessarily mean that the context is
detached.

Every time a JS function is called within a context that has a non-zero
DetachedWindowReason, Runtime::kReportDetachedWindowAccess is invoked,
which will report this call to Blink via a callback, which in turn can
report number of such calls via UKM metrics.

Bug: chromium:1018156
Change-Id: I67c89fef459f4efcb912229eed8a4f3ea3b60f54
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1862829
Auto-Submit: Bartek Nowierski <bartekn@chromium.org>
Commit-Queue: Bartek Nowierski <bartekn@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64707}