[sms] Restrict SMS Receiver API to Top Level Frames in Browser Process

This change restricts the SMS Receiver API to only be used from
top level frames to prevent malicious sites from accessing the one time
passcodes for signup. This change adds restrictions in the browser
process. Restriction in the renderer process can be found
here (https://crrev.com/c/1594211).

Bug: 936659
Change-Id: I95f38f178519fdacc35cb923716f2516b4f90d1b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1613718
Reviewed-by: Ken Buchanan <kenrb@chromium.org>
Reviewed-by: Alex Moshchuk <alexmos@chromium.org>
Reviewed-by: Reilly Grant <reillyg@chromium.org>
Commit-Queue: Ayu Ishii <ayui@chromium.org>
Cr-Commit-Position: refs/heads/master@{#662408}
7 files changed