Extracted this out of #5649
This commit was created with the following commands:
```
find . -iname "*.webidl" -type f -print0 | xargs -0 sed -i '' 's/http:\(.*\)whatwg.org/https:\1whatwg.org/g'
```
```
find . -iname "*.rs" -type f -print0 | xargs -0 sed -i '' 's/http:\(.*\)whatwg.org/https:\1whatwg.org/g'
```
Source-Repo: https://github.com/servo/servo
Source-Revision: 4997d3a112354a407365fede1ab1944834a2e13c
Still need to impl `Activatable` on all activatable elements. I'll probably push those changes to this PR, however they can be made separately as well.
Source-Repo: https://github.com/servo/servo
Source-Revision: 19c69b1625dda46d3c5501292e7e2d0328e400b4
