chromium: update to latest channel releases (security)

Fixes at least:

  - CVE-2016-1667
  - CVE-2016-1668
  - CVE-2016-1669
  - CVE-2016-1670
  - CVE-2016-5170
  - CVE-2016-5171
  - CVE-2016-5172
  - CVE-2016-5173
  - CVE-2016-5174
  - CVE-2016-5175
  - CVE-2016-7395

cc #18856