Get linux vulkan running on Intel NUC

This CL includes a few things.

First, it creates two CIPD assets, a Debug and Release version
of the Linux Vulkan Intel Driver. The driver is still young, 
so the Debug version helps us submit better bugs to the 
developers.  The current version is Mesa 13.04:
ftp://ftp.freedesktop.org/pub/mesa/13.0.4/

Second, it fixes the GN flavor to not purge out all environment
variables - a leftover from the GYP -> GN migration.

Third, it sets environment variables on both Test and Perf such
that the vulkan sdk, libraries and drivers all linked in from
their homes in CIPD.

BUG=skia:6133

Change-Id: I9a999e24a0203ab7a9f4733bee1110b79e616935
Reviewed-on: https://skia-review.googlesource.com/7994
Reviewed-by: Eric Boren <borenet@google.com>
Commit-Queue: Kevin Lubick <kjlubick@google.com>

0 files changed, 0 insertions, 0 deletions