Back in August, Google announced that they would be “de-emphasizing” Adobe Flash Player in Google Chrome. HTML 5 will be loaded in place of Flash except for sites that only support Flash. For those sites, you will be prompted to enable the browser plug-in.
In September and with Chrome 42, Chrome disabled Flash content that was loading behind the scenes, typically related to website analytics. Taking the next step, Chrome will disable Flash if HTML 5 is an option beginning with December. This is most likely to happen starting on December 6th with the arrival of Chrome 56.
In December, Chrome 55 will make HTML5 the default experience, except for sites which only support Flash. For those, you’ll be prompted to enable Flash when you first visit the site
The reason Google is pushing the move away from Flash is not surprising, as Flash has been frequently, publicly hated upon but the main reason is for security and power-efficiency reasons. Microsoft Edge has certainly been advertising the power efficiency of their browser for better battery life.
In slightly related news, Mozilla Firefox also previously announced that they would be disabling Java within their browser in 2016. So far, the (32-bit version, at least) still allows Java to work, another power and security drain.