Webrequest speculative (#2752)
Webrequest speculative (#2752)

* Alphabetize ResourceType subfeatures

* Add 'speculative' ResourceType

mdn/browser-compat-data,chrisdavidmills/browser-compat-data,teoli2003/browser-compat-data,chrisdavidmills/browser-compat-data,mdn/browser-compat-data