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

Source/core/xml/XSLTProcessor.cpp

Index: Source/core/xml/XSLTProcessor.cpp
diff --git a/Source/core/xml/XSLTProcessor.cpp b/Source/core/xml/XSLTProcessor.cpp
index d346ec6ab90bec90f8128bcc08d732a8d80258a5..559a7bb0383551608b0d5c2d56e985ee07d424bb 100644
--- a/Source/core/xml/XSLTProcessor.cpp
+++ b/Source/core/xml/XSLTProcessor.cpp
@@ -139,6 +139,8 @@ void XSLTProcessor::setParameter(const String& /*namespaceURI*/, const String& l
 {
     // FIXME: namespace support?
     // should make a QualifiedName here but we'd have to expose the impl
+    if (localName.isNull() || value.isNull())
+        return;
     m_parameters.set(localName, value);
 }
 
@@ -146,12 +148,16 @@ String XSLTProcessor::getParameter(const String& /*namespaceURI*/, const String&
 {
     // FIXME: namespace support?
     // should make a QualifiedName here but we'd have to expose the impl
+    if (localName.isNull())
+        return String();
     return m_parameters.get(localName);
 }
 
 void XSLTProcessor::removeParameter(const String& /*namespaceURI*/, const String& localName)
 {
     // FIXME: namespace support?
+    if (localName.isNull())
+        return;
     m_parameters.remove(localName);
 }