More edits

Fixup

Cleanup

Add language for content

Add shadow root serialization

Link to new "attach a shadow root" algorithm. Added exception handling.

Add early-out for topmost node

Added shadowroot to HTMLTemplateElement for feature detection

Addressed annevk's comments

Add available_to_internals = true

Add declarative shadow dom opt-in mechanics

Trying, unsuccessfully, to get rid of "parse error while closing p element"

Remove data-x for instance checks

Merge fixup

Rename include shadow roots state

Strip out serialization stuff

Lint cleanup

Fix closing tags

Fix dfn

Fix conformance error

Address all comments

Fix lint

First cut at streaming DSD definition

Address some comments

Address @rniwa comments

Capitalization

Rename shadowrootmode and add clonable

Address comments

Address comments

Line length

Fix regular document parsing

Address comments

Update to match DOM's new `declarative`

Clean up call to attach a shadow root

Address speculative parser comment

Replace tri-state with boolean

Allow about:blank

Address annevk comments

Address annevk comments

Report the exception