Introduce ShouldUseIsolatedCodeCache helper

This helper encapsulates decision about whether to use isolated
code cache, and will be used from both ResourceLoader and DocumentLoader.

Bug: none
Change-Id: Id04f4f3bdea716dc6d11bfd6a42b8962f4cbdec8
Reviewed-on: https://chromium-review.googlesource.com/c/1415691
Commit-Queue: Dmitry Gozman <dgozman@chromium.org>
Reviewed-by: Ben Kelly <wanderview@chromium.org>
Cr-Commit-Position: refs/heads/master@{#623541}
3 files changed