Add the ParentNode and NonDocumentTypeChildNode typedefs
Add the ParentNode and NonDocumentTypeChildNode typedefs

See https://dom.spec.whatwg.org/#parentnode and
https://dom.spec.whatwg.org/#nondocumenttypechildnode.

This adds the properties defined on Element only in
browser/w3c_elementtraversal.js to the ParentNode interface implemented
by Document, DocumentFragment and Element, and the
NonDocumentTypeChildNode interface implemented by Element and
CharacterData.

Merge pull request #1726 from Dominator008/closure-compiler
Closes https://github.com/google/closure-compiler/pull/1726
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=120834179

tiobe/closure-compiler,tiobe/closure-compiler,shantanusharma/closure-compiler,GerHobbelt/closure-compiler,superkonduktr/closure-compiler,redforks/closure-compiler,google/closure-compiler,LorenzoDV/closure-compiler,tdelmas/closure-compiler,MatrixFrog/closure-compiler,monetate/closure-compiler,ChadKillingsworth/closure-compiler,shantanusharma/closure-compiler,ChadKillingsworth/closure-compiler,nawawi/closure-compiler,Medium/closure-compiler,GerHobbelt/closure-compiler,redforks/closure-compiler,mprobst/closure-compiler,tiobe/closure-compiler,Dominator008/closure-compiler,brad4d/closure-compiler,nawawi/closure-compiler,tdelmas/closure-compiler,LorenzoDV/closure-compiler,google/closure-compiler,anomaly/closure-compiler,tdelmas/closure-compiler,tiobe/closure-compiler,anomaly/closure-compiler,Medium/closure-compiler,google/closure-compiler,Yannic/closure-compiler,shantanusharma/closure-compiler,mprobst/closure-compiler,redforks/closure-compiler,superkonduktr/closure-compiler,Yannic/closure-compiler,google/closure-compiler,MatrixFrog/closure-compiler,tdelmas/closure-compiler,Yannic/closure-compiler,vobruba-martin/closure-compiler,vobruba-martin/closure-compiler,ChadKillingsworth/closure-compiler,mprobst/closure-compiler,shantanusharma/closure-compiler,Dominator008/closure-compiler,monetate/closure-compiler,Medium/closure-compiler,nawawi/closure-compiler,LorenzoDV/closure-compiler,anomaly/closure-compiler,Pimm/closure-compiler,superkonduktr/closure-compiler,monetate/closure-compiler,vobruba-martin/closure-compiler,vobruba-martin/closure-compiler,MatrixFrog/closure-compiler,brad4d/closure-compiler,Pimm/closure-compiler,monetate/closure-compiler,MatrixFrog/closure-compiler,nawawi/closure-compiler,GerHobbelt/closure-compiler,Dominator008/closure-compiler,superkonduktr/closure-compiler,Yannic/closure-compiler,GerHobbelt/closure-compiler,brad4d/closure-compiler,mprobst/closure-compiler,Pimm/closure-compiler,anomaly/closure-compiler,ChadKillingsworth/closure-compiler