Since September of last year Intel developers have been porting Chromium to Wayland so it's not reliant upon X11. The port involved developing an Ozone-Wayland component with the Ozone framework basically handling the windowing system / input abstraction and other lower-level tasks for Chromium, Chrome, and Chrome OS. Intel's invested a lot of work in making Ozone-Wayland work well and it is indeed working well and most recently deployed for Tizen IVI.
Canonical has now brought Chromium to Mir via Ozone-Mir, which is a fork of Ozone-Wayland. Robert Carr acknowledged with Ozone-Mir, "Initial investigation in to Ozone Mir quickly lead to the observation that a large amount of code would need to be duplicated between them. In order to try to improve this situation, we have instead based our Ozone Mir work off of Ozone Wayland. Ozone Mir creates a new set of interfaces on the GPU process side abstracting the idea of utilizing an external EGL compositor."
Carr also wrote, "Chromium running on Mir is the first and biggest step towards running Chromium in Unity 8, ensuring a diverse browser ecosystem for the future of Ubuntu...Moving forward we are engaging with the Chrome team and Ozone Wayland engineers to develop a plan to move such a layer of interfaces upstream, enabling an easy life of collaboration for Ozone Wayland and Mir."
Robert Carr announced the Chromium Mir work on his Google+ page. Below is a video of Chromium on Mir.