RE: [cssom] Make CSSStyleSheet constructable

[Boris Zbarsky:]
> 
> On 10/17/12 8:33 PM, Boris Zbarsky wrote:
> > I'm not sure why.  Gecko already does such sharing on the style data
> > of linked stylesheets.  It would be easy to extend it to inline
> > stylesheets if needed.
> 
> One comment here, though: what Gecko actually does is a copy-on-access
> setup where sheets are shared as long as you don't touch their CSSOM.
> Once you do, the sharing stops, because at that point the sharing would be
> observable.
> 
Indeed I was wondering why this was a JS constructor issue vs. an 
implementation-level copy-on-write strategy?