Enable W3C encrypted-media tests

Now that the tests have been renamed to .https.html (so that they run
as https), reneable the few W3C encrypted-media tests that run with
content_shell.

BUG=664193
TEST=enabled tests pass

Change-Id: I52eae39ad500944a1c05129fe04f112ccaf1f676
Reviewed-on: https://chromium-review.googlesource.com/785797
Reviewed-by: Xiaohan Wang <xhwang@chromium.org>
Commit-Queue: John Rummell <jrummell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#519361}
1 file changed