[Extensions] CHECK() optional permissions when granting/removing

When granting and removing optional permissions from an extension in
PermissionsUpdater::GrantOptionalPermissions() and
PermissionsUpdater::RevokeOptionalPermissions(), CHECK() that the
permissions we're adding or removing are contained within the
optional permissions specified in the extension's manifest.

This required updating three unit tests that were exercising
improper behavior (trying to add or remove permissions that weren't
listed in the manifest).

Bug: None

Change-Id: I325ef2fb8c053b4ae7463aca36e6b4aba0ff4838
Reviewed-on: https://chromium-review.googlesource.com/c/1354651
Reviewed-by: Karan Bhatia <karandeepb@chromium.org>
Commit-Queue: Devlin <rdevlin.cronin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#612818}
3 files changed