This is a reland of c9fe34f2, which updates
a new call site of mojo::MakeIsolatedRequest that was introduced after the
the CL went through the CQ try jobs but before the CL landed.

Original change's description:
> Avoid using `isolated` wrt. AssociatedInterfaces.
> 
> The term `isolated` is already widely used for origins. Using it also
> to describe AssociatedInterfacePtrs and AssociatedInterfaceRequests
> that are associated with dedicated or a disconnected message pipe 
> (mostly for testing) is confusing. Instead, use the words `dedicated`
> and `disconnected`, respectively.
> 
> Bug: 729021
> Cq-Include-Trybots: master.tryserver.chromium.linux:linux_site_isolation
> Change-Id: Ie44893453fc0033f09eecac41af725f5123d07e4
> Reviewed-on: https://chromium-review.googlesource.com/743011


> Reviewed-by: John Abd-El-Malek <jam@chromium.org>
> Reviewed-by: Daniel Cheng <dcheng@chromium.org>
> Reviewed-by: Yuzhu Shen <yzs...