enterVR function does not work in setTimeout

Calling document.querySelector('a-scene').enterVR() from within setTimeout does not work on Chrome for Android . Throws:

webvr-polyfill.js:6442 Uncaught (in promise) DOMException: The play() request was interrupted by a call to pause(). https://goo.gl/LdLk22
M.release @ webvr-polyfill.js:6442
A @ webvr-polyfill.js:1308

a-scene.js:178 Uncaught (in promise) Error: Failed to enter VR mode (`requestPresent`): Unable to present.
    at i (a-scene.js:178)
    at <anonymous>

and aframe does not enter in VR mode.

Actual code:

setTimeout(function(){
    document.querySelector('a-scene').enterVR();
}, 2000);

Although, if I type document.querySelector('a-scene').enterVR(); from console, it works as expected.

On Chrome (version 64.0.3282.186) for Linux (Elementary OS 0.4.1 based on Ubuntu 16.04): If I try this from setTimeout, aframe does enter in VR mode but not in fullscreen, from console without setTimeout it works as expected

• A-Frame Version: 0.7.0
• Platform / Device: Chrome on Android and Linux version 64.0.3282.137
• Reproducible Code Snippet or URL: https://codepen.io/JFarrow/full/pNmdXa/ (same issue happens on any web page)

If you need any more information pardon me and please ask.
Thanks, a lot for this library.

[dmarcos]

Browsers are starting to enforce user gesture as well to access the motion sensors (DeviceMotionEvents). More context: https://github.com/aframevr/aframe/issues/4287

[dmarcos]

Chrome for iOS might not be applying the standard policy