Great. But please read through the following before filing a bug:
* We've got quite a lot of support already, please checkout [https://developer.mozilla.org/en-US/Add-ons/WebExtensions the existing APIs].
* The goal of WebExtensions is not to support every API and use case from legacy extensions.
* For a list of what we are aiming for, please check out [[WebExtensions/Vision|the vision document]]