Resource Priorities spec updates
- Removed extension declarations from each partial interface
- Removed 'readonly' from IDL attribute definitions
- lazyload MUST clause updated to SHOULD
- Defined content and IDL attribute definitions for lazyload and postpone
- Clarified that readyState IDL attribte and DOMContentLoaded events are not impacted by lazyload or postpone
- Clarified that if no lazyload elements exist, lazyloaded event fires immediately after load event
- Added 'resource-priorities' CSS property
- Postpone only impacts audio element if controls boolean attribute is specified
- Parser will not block launching new scripts on lazyloaded stylesheets
- Rendering will not be blocked on lazyloaded stylesheets
- Added SVG image, use, script, and tref elements
- Added SVG 1.1 reference
- Lazyload and postpone have no effect on svg feImage when externalResourcesRequired is true
- Updated attribution section
Merge