Update libjpeg-turbo to r856.

BUG=132952
TEST=none
Review URL: https://chromiumcodereview.appspot.com/10700197

git-svn-id: http://src.chromium.org/svn/trunk/deps/third_party/libjpeg_turbo@147403 4ff67af0-8c30-449e-8e8b-ad334ec8d88c
12 files changed