Extracted out of #5649
* add more hyperlinks to associated specification for structs/methods
* follow redirects and update links
* replace broken links
* removal of WHATWG multipage page name since the page name is not
guaranteed to be stable
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'
```
Transition events are not yet supported, and the only animatable
properties are `top`, `right`, `bottom`, and `left`. However, all other
features of transitions are supported. There are no automated tests at
present because I'm not sure how best to test it, but three manual tests
are included.
`cellspacing` attribute per HTML5 § 14.3.9.
Table layout code has been refactored to push the spacing down to
rowgroups and rows; this will aid the implementation of
`border-collapse` as well.
This commit also fixes two nasty issues in table layout:
* In fixed layout, extra space would not be divided among columns that
had auto width but had nonzero minimum width.
* In automatic layout, extra space would be distributed to constrained
columns as well even if unconstrained columns with percentage equal to
zero were present.
§ 12.3-12.5.
Only simple alphabetic and numeric counter styles are supported. (This
is most of them though.)
Although this PR adds a sequential pass to layout, I verified that on
pages that contain a reasonable number of ordered lists (Reddit
`/r/rust`), the time spent in generated content resolution is dwarfed by
the time spent in the parallelizable parts of layout. So I don't expect
this to negatively affect our parallelism expect perhaps in pathological
cases.
Instead of simply creating a new FrameTree when an iframe starts a
load, update the existing FrameTree's pipeline. This prevents the
FrameTree from accumulating many extra children.
Additionally, this patch cleans up some miscellaneous formatting issues
and refactors files in `layout/css/` somewhat to eliminate needless
levels of indirection. It also fixes our handling of presentational
hints that only apply if border is nonzero.
When inserting a node that was already dirtied, the dirtying logic
would short circuit: "This node is already dirty? Great! Then its
parents must be HAS_DIRTY_DESCENDANTS, too! Let's skip that step."
This isn't appropriate when nodes move around the tree. In that case,
the node may be marked HAS_CHANGED, but ancestors may not yet have
the HAS_DIRTY_DESCENDANTS flag set.
This patch adds a `content_and_heritage_changed` hook in the document,
to deal with these cases appropriately.
