Implement Style sheet set API according to CSSOM spec

[HE Shi-Jun]

[Supplemental] interface Document {
  readonly attribute StyleSheetList styleSheets;
           attribute DOMString? selectedStyleSheetSet;
  readonly attribute DOMString? lastStyleSheetSet;
  readonly attribute DOMString? preferredStyleSheetSet;
  readonly attribute DOMStringList styleSheetSets;
  void enableStyleSheetsForSet(DOMString? name);
};

See: http://dev.w3.org/csswg/cssom/#extensions-to-the-document-interface

There are some bugs on alternate stylesheets.
See:
#56932: Alternate stylesheets are not present in document.styleSheets 
#26673: Dynamically changing .disabled doesn't work 

And other bugs:
For alternate stylesheets, element.disabled and element.sheet.disabled should be true, but currently they are false. 
And set element.sheet.disabled does not affect element.disabled...

[Alexey Proskuryakov]

This bug is not very useful as filed. CSSOM is a large specification, and large specifications typically never get implemented to 100% in any browser. When would you consider this bug resolved?

If there is anything specific that you need and that is not implemented in WebKit, it would be most efficient to provide your use cases for the features that are needed.

[Kevin Ballard]

This bug as filed isn't asking for full implementation of CSSOM but rather an implementation of the Stylesheet Set API.

[Alexey Proskuryakov]

Still, what is the specific bug to be fixed here? 

We implement many parts of the API. Propagation of disabled flag thats mentioned in bug description 's being worked on in other bugs. What exactly needs to be done to consider this bug report finished?

[Kevin Ballard]

(In reply to comment #3)
> Still, what is the specific bug to be fixed here? 
> 
> We implement many parts of the API. Propagation of disabled flag thats mentioned in bug description 's being worked on in other bugs. What exactly needs to be done to consider this bug report finished?

I would imagine that, at the very least, the API that's listed in the description needs to be implemented. Right now webkit supports styleSheets, selectedStylesheetSet (capitalization difference is covered by bug #62407) and preferredStylesheetSet, but it doesn't support lastStyleSheetSet, styleSheetSets, or enableStyleSheetsForSet().

[Radar WebKit Bug Importer]

<rdar://problem/96911947>