Add adapter LUID to EGL vendor string.

This is so Chrome can create another D3D device on the same adapter that can share resources with ANGLE's D3D device.
Review URL: https://codereview.appspot.com/9225046

git-svn-id: http://angleproject.googlecode.com/svn/trunk@2210 736b8ea6-26fd-11df-bfd4-992fa37f6226