Cleanup after transition to new attestation dbus methods.

The methods with the 'New' suffix are temporary and will soon be
removed.

BUG=chromium:243605
TEST=manual

Review URL: https://codereview.chromium.org/213413009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@260428 0039d316-1c4b-4281-b951-d872f2087c98
  CryptohomeClientImpl() : proxy_(NULL), weak_ptr_factory_(this) {}

  CryptohomeClientImpl() : proxy_(NULL), weak_ptr_factory_(this) {}
