Add CdmWrapper to support multiple CDM versions in CdmAdapter.

CdmWrapper wraps different versions of ContentDecryptionModule interfaces and exposes a common interface to the caller.

BUG=306647
TEST=none

Review URL: https://codereview.chromium.org/26155003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@229571 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 229571
Use local NTP if the NTP is blocked for a supervised user.

BUG=290961

Review URL: https://codereview.chromium.org/26262002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@229572 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 229572