Add Autofill preview support for <select> input fields

Source/core/testing/Internals.idl

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  * Copyright (C) 2013 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 98 matching lines @@
 
     [RaisesException] DOMString viewportAsText(Document document,
                                                float devicePixelRatio,
                                                long availableWidth,
                                                long availableHeight);
 
     [RaisesException] boolean wasLastChangeUserEdit(Element textField);
     [RaisesException] boolean elementShouldAutoComplete(Element inputElement);
     [RaisesException] DOMString suggestedValue(Element inputElement);
     [RaisesException] void setSuggestedValue(Element inputElement, DOMString value);
+    [RaisesException] DOMString originalValue(Element inputElement);
+    [RaisesException] void setOriginalValue(Element inputElement, DOMString value);
     [RaisesException] void setEditingValue(Element inputElement, DOMString value);
     [RaisesException] void setAutofilled(Element inputElement, boolean enabled);
 
     [RaisesException] void paintControlTints(Document document);
 
     [RaisesException] void scrollElementToRect(Element element, long x, long y, long w, long h);
 
     [RaisesException] Range rangeFromLocationAndLength(Element scope, long rangeLocation, long rangeLength);
     [RaisesException] unsigned long locationFromRange(Element scope, Range range);
     [RaisesException] unsigned long lengthFromRange(Element scope, Range range);
@@ skipping 138 matching lines @@
     boolean isSelectPopupVisible(Node node);
 
     [RaisesException] ClientRect selectionBounds();
 
     boolean loseSharedGraphicsContext3D();
 
     [RaisesException] void forceCompositingUpdate(Document document);
 
     void setZoomFactor(float factor);
 };