Roll 50: Copied IDLs, PYTHON scripts from WebKit removed deleted files in WebCore

core/dom/Text.idl

 /*
  * Copyright (C) 2006 Apple Computer, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 11 matching lines @@
 [
     Constructor(optional DOMString data = ""),
     ConstructorCallWith=Document,
 ] interface Text : CharacterData {
     [NewObject, RaisesException] Text splitText(unsigned long offset);
     [MeasureAs=TextWholeText] readonly attribute DOMString wholeText;
 
     // Shadow DOM
     // http://w3c.github.io/webcomponents/spec/shadow/#extensions-to-text-interface
     NodeList getDestinationInsertionPoints();
+    [RuntimeEnabled=ShadowDOMV1, ImplementedAs=assignedSlotForBinding] readonly attribute HTMLSlotElement assignedSlot;
 };