UserAgent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/66.0.3359.117 Safari/537.36

Steps to reproduce the problem:
1. Go to https://threejs.org/examples/?q=vive#webvr_vive_dragging or https://www.with.in/watch/under-neon-lights/
2. Hit the "Enter VR Button"
3. See Controller placed in the virtual world
4. Move hands around and see Controller is paired to position quite well for 6do
5. Pull the trigger and let go.

What is the expected behavior?
On https://threejs.org/examples/?q=vive#webvr_vive_dragging the expected behavior is to click and drag objects in the 3D virtual space.

On https://www.with.in/watch/under-neon-lights/ the expected behavior is that the experience starts.

What went wrong?
Pulling the trigger doesn't fire the intended button on / button off events expected from the Gamepad API.

I file this under the WebVR API because initiating presenting to HMD and exiting presenting from HMD triggers the button event from the Gamepad API. This was confirmed in the Under Neon Lights example because as soon as you take off the headset the experience starts.

Did this work before? N/A 

Does this work in other browsers? Yes

Chrome version: 66.0.3359.117  Channel: stable
OS Version: 10.0
Flash Version: 

This works on Firefox and MS Edge stable candidates.