Only allows the badge to be set when inside app scope in a hosted app.

Previously, if you navigated to another site inside the PWA that site
could set a badge.

Bug: 719176
Change-Id: If9a41a90751f4806d0d61927cd80a2ac77bfcc06
Reviewed-on: https://chromium-review.googlesource.com/c/1362680
Commit-Queue: Jay Harris <harrisjay@chromium.org>
Reviewed-by: Matt Giuca <mgiuca@chromium.org>
Cr-Commit-Position: refs/heads/master@{#617030}
4 files changed