WebVR is now available in Chrome Canary!
Previously there were custom, experimental builds of Chromium hosted here that gave developers early access to WebVR on Windows. Hovewer, they were severely outdated and had known security issues.
At this point you can get better, faster, safer access to WebVR on Windows with the official Chrome releases, version 65+ (Available in Canary builds as of his writing).
In order to enable access to the WebVR APIs in the official Chrome builds you must select the "Enabled" option from the drop-down menu for the "Enable WebVR" flag (enter
chrome://flags/#enable-webvr in the URL bar) and the "Gamepad Extensions" flag (enter
chrome://flags/#enable-gamepad-extensions in the URL bar) and the "OpenVR Hardware Support" flag (enter
chrome://flags/#openvr in the URL bar)
(Direct support for the Oculus SDK is coming soon, but in the meantime the Rift appears to work fine with the OpenVR backend.)
If absolutely necessary you can still access the deprecated build list here.
WARNING: All chromium builds on that list are experimental! They have not been vetted by Google, me, nor anyone else for security or stability, and under no circumstances should you use them as your day-to-day browser! They are provided for testing of the experimental WebVR APIs only. Not only that, at this point they're old and better support is available via official channels. You really have no good excuse for using them.