[ Feature Policy ] Followup on Opener Policies

Desktop / Chromium - Ehsan Karamad [chromium.org] - 26 February 2019 20:55 EST

This CL fixes a few types and mistakes in the original CL which implemented opener policies (CL: 1384992).

Besides, this CL adds two WPTs to complement the test coverage for "FeaturePolicyForSandbox". The current tests verify correctness of propagation in the following cases:

1- "window.open" from an