Gecko doesn't really follow the spec but it seems to throw a HierarchyRequest error when parent is null.
Any ideas who I should talk to about fixing the spec to account for the null checks?
Source-Repo: https://github.com/servo/servo
Source-Revision: acf47a02cf38b5c82e7c78cc1f6660a7daa9969a
The actual boundary points are behind a Rc<_> value to let nodes be able to store weak references to them in the future.
Source-Repo: https://github.com/servo/servo
Source-Revision: 15c4372a8be9c2b73d9e09bd7684484e48d220e8
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
