Move Stylesheet loading and ownership from the layout task into HTML elements
Stylesheets for `HTMLLinkElement`s are now loaded by the resource task, triggered by the element in question. Stylesheets are owned by the elements they're associated with, which can be `HTMLStyleElement`, `HTMLLinkElement`, and `HTMLMetaElement` (for `<meta name="viewport">).
Additionally, the quirks mode stylesheet (just as the user and user agent stylesheets a couple of commits ago), is implemented as a lazy static, loaded once per process and shared between all documents.
This all has various nice consequences:
- Stylesheet loading becomes a non-blocking operation.
- Stylesheets are removed when the element they're associated with is removed from the document.
- It'll be possible to implement the CSSOM APIs that require direct access to the stylesheets (i.e., ~ all of them).
- Various subtle correctness issues are fixed.
One piece of interesting follow-up work would be to move parsing of external stylesheets to the resource task, too. Right now, it happens in the link element once loading is complete, so blocks the script task. Moving it to the resource task would probably be fairly straight-forward as it doesn't require access to any external state.
Depends on #7979 because without that loading stylesheets asynchronously breaks lots of content.
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Stylesheets for `HTMLLinkElement`s are now loaded by the resource task, triggered by the element in question. Stylesheets are owned by the elements they're associated with, which can be `HTMLStyleElement`, `HTMLLinkElement`, and `HTMLMetaElement` (for `<meta name="viewport">).
Additionally, the quirks mode stylesheet (just as the user and user agent stylesheets a couple of commits ago), is implemented as a lazy static, loaded once per process and shared between all documents.
This all has various nice consequences:
- Stylesheet loading becomes a non-blocking operation.
- Stylesheets are removed when the element they're associated with is removed from the document.
- It'll be possible to implement the CSSOM APIs that require direct access to the stylesheets (i.e., ~ all of them).
- Various subtle correctness issues are fixed.
One piece of interesting follow-up work would be to move parsing of external stylesheets to the resource task, too. Right now, it happens in the link element once loading is complete, so blocks the script task. Moving it to the resource task would probably be fairly straight-forward as it doesn't require access to any external state.
Update mozjs
r? @Manishearth
This mainly just picks up the support for ccache. I'd like to get one module using it to land to see how it works on Travis & the builders (probably should have done this along with #8366).
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We cache the state of any live HTMLCollection, keeping track of
a) the optional cached length of the collection, and
b) an optional cursor into the collection (a node in the collection plus its index).
The cache is invalidated based on the version number of the node.
We use these caches for speeding up random access to the collection.
When returning coll[i], we search from the cursor, if it exists,
and otherwise search from the front of the collection.
In particular, both a forward for-loop and a backward for-loop
through the collection will now have each access take O(1)
time rather than O(n) time.
This gets 1000x speed-up on the relevant Dromaeo DOM query tests.
There is now an inclusive_descendants_version field of each node, which
increases each time the node, or any of its descendants, is dirtied.
This can be used for cache invalidation, by caching a version number
and comparting the current version number against the cached version number.
Draft. Change PaintContext rects to TypedRects #7023
I created draft. I'm not sure if we need any units conversion in PaintContext. There is also strange 'clear' method, we use PagePx origin and ScreenPx size is it OK?
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