Google is in the process of adding dual-screen support for Google Chrome for Android.
A commit on Chromium Review by Googler Lijin Shen notes:
Add support for android multiple display Tabs can be moved to the secondary display. 1. when the secondary display is disconnected, #onDisplayRemoved will be called immediately. The activity on removed display will be recreated if the dpi on removed display is not same with the remaining display.
The feature would let you have two tabs on side by side displays, move one tab to another or open a link in “another window”.
The option is only available in dual-screened devices such as the Surface Duo and can be activated with the “multiple display” flag.