Google will be taking another step towards an HTML5-only Web later this year, as the systematic deprecation and removal of Flash continues.
There will be a few exceptions to this policy, with Google planning to leave Flash enabled by default on the top 10 domains that depend on the plugin. This list includes YouTube, Facebook, Twitch, and Amazon. Even this reprieve is temporary. The plan is to remove sites from the list whenever possible—Twitch, for example, is switching to HTML5 streaming, so should start to phase out its use of Flash—and after one year the whitelist will be removed entirely. This means that after the fourth quarter 2017, Flash will need to be explicitly enabled on every site that tries to use it.