In a Google Groups thread named "Intent to implement: HTML5 by Default," the Google developers announced initial plans to implement a new feature in the Chromium core that will disable the playback of Flash content by default, and use HTML5 instead, if available.
The feature is scheduled to ship with Chromium builds in Q4 2016, according to the current timeline.
"If a site offers an HTML5 experience, this change will make that the primary experience," Anthony LaForge, Technical Program Manager at Google explained. "We will continue to ship Flash Player with Chrome, and if a site truly requires Flash, a prompt will appear at the top of the page when the user first visits that site, giving them the option of allowing it to run for that site."
The Chromium team will basically implement a permanent "Ask to activate" feature for all websites running Flash content, similar to what Firefox has been optionally providing its users for some time now.
"This change reflects the maturity of HTML5 and its ability to deliver an excellent user experience," LaForge also noted. "While Flash historically has been critical for rich media on the web, today in many cases HTML5 provides a more integrated media experience with faster load times and lower power consumption."