Specs: Drop the concept of late-bound elements. An element can never be upgraded.

Specs: Drop the concept of late-bound elements. An element can never be upgraded.

This has the following implications:

 - There's no createElement() function any more. If you want to create
   an element from script, you have to use its constructor.

 - There's no async element registration. The parser will block until
   all the imports are imported when you use a tag name of a custom
   element that hasn't been registered yet, in case one of the imports
   defines it.

 - If you try to construct a non-registered element in markup, it
   turns into an <error> element.

 - <div>, <span>, and <error> are new built-in elements.

R=esprehn@chromium.org

Committed: https://chromium.googlesource.com/external/mojo/+/a3dae915ea6f9e688551fa8e90e59ba0e7749c7a

[esprehn, 2014-11-04 00:48:39]

esprehn@chromium.org changed reviewers:
+ esprehn@chromium.org

[esprehn, 2014-11-04 00:48:40]

lgtm

[Hixie, 2014-11-04 00:52:51]

Committed patchset #1 (id:1) manually as
a3dae915ea6f9e688551fa8e90e59ba0e7749c7a (presubmit successful).