[binding] Migrate XSLTProcessor.idl away from using custom V8 binding.

LayoutTests/fast/xsl/xslt-processor-expected.txt

 CONSOLE WARNING: Synchronous XMLHttpRequest on the main thread is deprecated because of its detrimental effects to the end user's experience. For more help, check http://xhr.spec.whatwg.org/.
 0.1 original xml:
 <?xml version="1.0" encoding="UTF-8"?><?xml-stylesheet type="text/xsl" href="xslt-text.xsl"?><TEST>SOURCE XML: &lt;&lt;&lt;&amp;тест&amp;&gt;&gt;&gt;</TEST>
 0.2 xsl1:
 <?xml version="1.0" encoding="UTF-8"?><xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
 
 <xsl:output method="text" encoding="KOI8-R"/>
 <xsl:template match="TEST">CHARACTERS IN XSLT: &lt;&lt;&lt;&amp;тест&amp;&gt;&gt;&gt;
 <xsl:apply-templates/><xsl:text>
 </xsl:text></xsl:template>
@@ skipping 65 matching lines @@
 3.2 transform twice:
 Success
 
 4.0 void setParameter(in DOMString namespaceURI, in DOMString localName, in Value value):
 
 4.1 pass setParameter same localname, different namespaces:
 ****Failure**** (expected: "Success" actual: "Failure")
 4.2 pass undefined namespace:
 Success
 4.3 pass setParameter an undefined name:
-****Failure**** (expected exception, instead got result: "undefined")
-4.4 pass unsupported value to setParameter:
+Success
+4.4 pass undefined value to setParameter:
+Success
+4.5 pass unsupported value to setParameter:
 ****Failure**** (expected exception, instead got result: "undefined")
 
 5.0 Value getParameter(in DOMString namespaceURI, in DOMString localName):
 
 5.1 pass getParameter an undefined name:
-****Failure**** (expected exception, instead got result: "undefined")
+Success
 5.2 pass getParameter a name which has not been set:
 Success
 5.3 verify getParameter actually gets (and set sets):
 Success
 
 6.0 void removeParameter(in DOMString namespaceURI, in DOMString localName):
 
 6.1 pass removeParameter same localname, different namespaces:
 ****Failure**** (expected: "Success" actual: "Failure")
 6.2 verify removeParameter actually removes using undefined namespace:
 Success
 6.3 pass removeParameter undefined name:
 Success
 6.4 pass removeParameter a name which has not been set:
 Success
 6.5 verify removeParameter actually removes:
 Success
 
 7.0 void clearParameters():
 
 7.1 verify that clearParameters does:
 Success
 
 8.0 void reset():
 
 8.1 verify that parameters have been cleared:
 Success
 8.2 verify that stylesheet has been cleared:
 Success