Match the spec regarding browsing context selection with noopener

Bug: 961816
Change-Id: Ie17882325e9acb124843e8a1f70e5a570738e2a8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1601653
Commit-Queue: Nate Chapin <japhet@chromium.org>
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#659158}
3 files changed