Blocked popup & mixed content dialogs better matches the Material Design mocks.

Added blocked popup content to interactive invocation of blocked popups dialog.

TBR=grt@chromium.org

Bug: 652031
Change-Id: I1c3f4bca0fe682897e0ed98e61957735b0d46320
Reviewed-on: https://chromium-review.googlesource.com/612496


Reviewed-by: Allen Bauer <kylixrd@chromium.org>
Reviewed-by: Adrienne Porter Felt <felt@chromium.org>
Reviewed-by: Peter Kasting <pkasting@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Allen Bauer <kylixrd@chromium.org>
Cr-Commit-Position: refs/heads/master@{#501278}