Web updates

DOM fc601be94e75

Change handling of is="" in element creation and cloning Part of fixing This changes two things: * It fixes the cloning steps to consult the internal is value, instead of the is="" content attribute. * It removes the step from createElement()/createElementNS() that would insert an is="" attribute in the created element, as we've now decided that is="" is a way of communicating to the parser, and not a general-purpose indicator of customized built-in-ness. See also for the other half of the fix. Tests:

Domenic Denicola

HTML e5dc6bf18f35

Update customized built-in elements is="" interaction This follows the DOM changes in, and is part of fixing The normative changes are to the serialization algorithm, which now writes out the element's is value as its is="" attribute, if no actual is="" attribute is present. The rest of the changes are to introductory text about customized built-in elements. Tests:

Domenic Denicola