Linux sandbox: restrict futex operations.

First-pass at restricting futex operations. We ban FUTEX_CMP_REQUEUE_PI, as it is
not used throughout Chrome.

BUG=377392
R=mdempsky@chromium.org

Review URL: https://codereview.chromium.org/314903002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@274934 0039d316-1c4b-4281-b951-d872f2087c98
11 files changed