Implemented XMLSerializer in PrivateScript.

Source/core/xml/XMLSerializer.idl

Index: Source/core/xml/XMLSerializer.idl
diff --git a/Source/core/xml/XMLSerializer.idl b/Source/core/xml/XMLSerializer.idl
index 1a7b6279dba8f46db31cd54994b0786295794a33..791afe5d9e73d0ab1d3fcf6ee596ecdc867d636f 100644
--- a/Source/core/xml/XMLSerializer.idl
+++ b/Source/core/xml/XMLSerializer.idl
@@ -20,8 +20,11 @@
 
 [
     WillBeGarbageCollected,
-    Constructor
+    Constructor,
+    ConstructorCallWith=Document
 ] interface XMLSerializer {
     [RaisesException] DOMString serializeToString([Default=Undefined] optional Node node);

[Jens Widell, 2014/09/03 10:29:33]

Unrelated to this CL: We could add [TypeChecking=Interface] to verify the 'node'
argument is valid instead of checking in C++. (And maybe drop 'optional' and
'[Default=Undefined]', since the argument doesn't really appear to be very
optional.)

[tasak, 2014/09/03 11:40:46]

Done.

+
+    [OnlyExposedToPrivateScript, ImplementedInPrivateScript] DOMString serializeToStringInternal(Node node, [Default=Undefined] optional DOMString xmlDeclaration);

[Jens Widell, 2014/09/03 10:29:33]

Make this "xmlDeclaration = ''" instead of [Default=Undefined]? (I doubt the
string "undefined" will work very well as an XML declaration.)

[tasak, 2014/09/03 11:40:46]

Done.

 };