Revert of Revert of Use BoringSSL in the implementation of ClearKey for Chromecast.

Revert of Revert of Use BoringSSL in the implementation of ClearKey for Chromecast. (patchset #1 id:1 of https://codereview.chromium.org/1141243003/)

Reason for revert:
OK to replay now

Original issue's description:
> 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
>
> Committed: https://crrev.com/564d81833f28f73b9413c6d01725530ff91de64c
> Cr-Commit-Position: refs/heads/master@{#330230}

TBR=ddorwin@chromium.org,dougsteed@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=488572
Committed: https://crrev.com/be51eda15009d0cd718c1f2aeab48fefd384a4b8
Cr-Commit-Position: refs/heads/master@{#330372}

[gunsch, 2015-05-18 16:26:41]

Created Revert of Revert of Use BoringSSL in the implementation of ClearKey for
Chromecast.

[commit-bot: I haz the power, 2015-05-18 16:27:30]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1148433002/1

[commit-bot: I haz the power, 2015-05-18 16:28:35]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-05-18 22:40:13]

Patchset 1 (id:??) landed as
https://crrev.com/be51eda15009d0cd718c1f2aeab48fefd384a4b8
Cr-Commit-Position: refs/heads/master@{#330372}