Switch media stream permissions to use IsOriginSecure() instead of SchemeIsSecure().

In particular, note that this means that media permissions are persisted on
http://localhost .

The change also updates the old media stream permission tests (which
were no longer testing anything meaningful).

(This is a reland of https://codereview.chromium.org/1276373004/ with a fixed
test, after it was reverted in https://codereview.chromium.org/1276373004/ )

BUG=295723, 362214, 509844

Review URL: https://codereview.chromium.org/1286363002

Cr-Commit-Position: refs/heads/master@{#343276}
8 files changed