https://bugs.webkit.org/show_bug.cgi?id=120691

Reviewed by Darin Adler.

Source/WebCore:

Have ProcessingInstruction inherit CharacterData as per the latest DOM4
specification:
http://dom.spec.whatwg.org/#processinginstruction

Previously, ProcessingInstruction was inheriting from Node as per DOM
Level 3.

Firefox and Blink already follow DOM4 here but not IE10.
This change leads to less code duplication.

Test: fast/dom/processing-instruction-inherit-characterdata.xhtml

* bindings/objc/PublicDOMInterfaces.h:
* dom/CharacterData.cpp:
(WebCore::CharacterData::setDataAndUpdate):
* dom/ProcessingInstruction.cpp:
(WebCore::ProcessingInstruction::ProcessingInstruction):
(WebCore::ProcessingInstruction::cloneNode):
(WebCore::ProcessingInstruction::checkStyleSheet):
(WebCore::ProcessingInstruction::insertedInto):
(WebCore::ProcessingInstruction::removedFrom):
(WebCore::ProcessingInstruction::finishParsingChildren):
* dom/ProcessingInstruction.h:
(WebCore::toProcessingInstruction):
* dom/ProcessingInstruction.idl:

LayoutTests:

Add layout test to validate that ProcessingInstruction inherits from
CharacterData.

* fast/dom/coreDOM-element-attribute-js-null-expected.txt:
* fast/dom/coreDOM-element-attribute-js-null.xhtml:
* fast/dom/processing-instruction-inherit-characterdata-expected.txt: Added.
* fast/dom/processing-instruction-inherit-characterdata.xhtml: Added.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@155340 268f45cc-cd09-0410-ab3c-d52691b4dbfc