Revert of Use BoringSSL in the implementation of ClearKey for Chromecast. (patchset #1 id:1 of https://codereview.chromium.org/1130893008/)

Reason for revert:
Temporary revert until Monday (blocked on some other internal changes).

Original issue's description:
> Use BoringSSL in the implementation of ClearKey for Chromecast.
> (Previously, this was used only with the "Chrome" branding).
>
> BUG= 488572
>
> R=gunsch@chromium.org
>
> Committed: https://crrev.com/defd2af08f3753687cb2d86b34bbec9da31ccbab
> Cr-Commit-Position: refs/heads/master@{#330156}

TBR=ddorwin@chromium.org,dougsteed@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG= 488572

Review URL: https://codereview.chromium.org/1141243003

Cr-Commit-Position: refs/heads/master@{#330230}
1 file changed