linux_aura: Revert everything; abort turning linux_aura on.

Spectacular breakages include:

- nacl integration tests constantly crashing.
- browser tests running in a busted environment.
- interactive_ui_tests being weirdly broken despite not running.
- Size regressions

BUG=125106,303342,304554,125106,304555
TBR=cpu@chromium.org,mseaborn@chromium.org,tim@chromiium.org,phajdan.jr@chromium.org,koz@chromium.org

Review URL: https://codereview.chromium.org/26157003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@227214 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 227214