Adds first cut implementation of a private key store abstraction for openssl
- this allows keygen created keys to be stored in a platform specific way, and looked up in client auth
- still needs additional work in CertDatabase to fully implement client auth

BUG=64917
TEST=Keygen unittest

Review URL: http://codereview.chromium.org/5594009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@68836 0039d316-1c4b-4281-b951-d872f2087c98
7 files changed