Remove mesa packages from install-build-deps

The mesa packages were originally added because of an issue with installing
libgbm-dev on Saucy.  The CL description is inlined below:

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commit: 419a9a64
Author: primiano@chromium.org <primiano@chromium.org@0039d316-1c4b-4281-b951-d872f2087c98>
Date: Thu Jun 19 18:26:18 2014 +0000

Fix installation of libgbm-dev package in install-build-deps.sh

crrev.com/106633002 has recently introduced a dependency on libgbm-dev.
Unfortunatelly, this package is a bit more trickier to install, for the
following reason: it depends on mesa-glx and, conversely to most of the
other packages, only one version of mesa (w.r.t backports) can exist in
the system. Google's workstations are configured to use the -lts-saucy
version of mesa. The right package in this case is libgbm-dev-lts-saucy
and attempting to install just libgbm-dev ends up in a failure.
This change fixes install-build-deps.sh, installing the matching version
of libgbm-dev (w.r.t libgl1-mesa-glx), falling back to libgbm-dev.
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Currently, this is causing issues on Googler's machines (see chrome-linux
mailing list).  Since the Saucy days are over, just depend on libgbm-dev
directly.  Tested on Ubuntu Trusty, Ubuntu Xenial, Debian Stretch, and Debian
Testing.

R=dpranke

Change-Id: I43568ab8b8c66c2aa6cd394c67f2cf90d6d1762c
Reviewed-on: https://chromium-review.googlesource.com/944047


Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Commit-Queue: Thomas Anderson <thomasanderson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#540271}