Skeleton for Ozone FrameBuffer implementation

Skeleton for Ozone FrameBuffer implementation

This cl simply makes the code compile on Ozone. It does not implement
the FrameBufferOzone class, but provides a skeleton for it, which can
be implemented by people on the ChromeOS team.

Change-Id: Ib77e20b00e8208d992c80f47b5ba55e00254c812
Reviewed-on: https://swiftshader-review.googlesource.com/11348
Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>