Full instructions for reference. Run:

  wget http://us.archive.ubuntu.com/ubuntu/pool/main/n/nss/libnss3{_3.16.3-1ubuntu1_amd64,-1d_3.16.3-1ubuntu1_amd64,-nssdb_3.16.3-1ubuntu1_all}.deb
  sudo dpkg -i libnss3*.deb

Create a new Tampermonkey script:

  // ==UserScript==
  // @name         Netflix HTML5 for Linux
  // @namespace    0d0a3443-cc79-4f86-bf62-2dac581d2b3a
  // @version      0.1
  // @description  Enables HTML5 video support for the Linux host platform
  // @match        *://www.netflix.com/WiPlayer?*
  // @user-agent   Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/37.0.2062.68 Safari/537.36
  // ==/UserScript==