Remove output protection pepper APIs

Now that CDMs use mojo exclusively, remove the Pepper APIs that are
now unused.

BUG=772160
TEST=compiles

Change-Id: I4161d7430f86f5033dd7997fb5f2cc4a04aefa22
Reviewed-on: https://chromium-review.googlesource.com/988254
Reviewed-by: Bill Budge <bbudge@chromium.org>
Reviewed-by: Xiaohan Wang <xhwang@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: Ben Smith <binji@chromium.org>
Commit-Queue: John Rummell <jrummell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#549671}
34 files changed