This update Chromium 53.0.2785.143 fixes the following issues (boo#1002140)

- CVE-2016-5177: Use after free in V8
- CVE-2016-5178: Various fixes from internal audits

The following bugfix changes are included:

- Export GDK_BACKEND=x11 before starting chromium, ensuring that it's started as an Xwayland client (boo#1001135).
- Changes to Sandbox to fix crashers on tumbleweed (boo#999091)