Add Autofill preview support for <select> input fields

Source/core/testing/Internals.cpp

 /*
  * 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 995 matching lines @@
         exceptionState.throwDOMException(InvalidNodeTypeError, "The element provided is not a form control element.");
         return String();
     }
 
     String suggestedValue;
     if (isHTMLInputElement(*element))
         suggestedValue = toHTMLInputElement(*element).suggestedValue();
 
     if (isHTMLTextAreaElement(*element))
         suggestedValue = toHTMLTextAreaElement(*element).suggestedValue();
+
+    if (isHTMLSelectElement(*element))
+        suggestedValue = toHTMLSelectElement(*element).suggestedValue();
+
     return suggestedValue;
 }
 
 void Internals::setSuggestedValue(Element* element, const String& value, ExceptionState& exceptionState)
 {
     if (!element) {
         exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(1, "Element"));
         return;
     }
 
     if (!element->isFormControlElement()) {
         exceptionState.throwDOMException(InvalidNodeTypeError, "The element provided is not a form control element.");
         return;
     }
 
     if (isHTMLInputElement(*element))
         toHTMLInputElement(*element).setSuggestedValue(value);
 
     if (isHTMLTextAreaElement(*element))
         toHTMLTextAreaElement(*element).setSuggestedValue(value);
+
+    if (isHTMLSelectElement(*element))
+        toHTMLSelectElement(*element).setSuggestedValue(value);
 }
 
 void Internals::setEditingValue(Element* element, const String& value, ExceptionState& exceptionState)
 {
     if (!element) {
         exceptionState.throwDOMException(InvalidAccessError, ExceptionMessages::argumentNullOrIncorrectType(1, "Element"));
         return;
     }
 
     if (!isHTMLInputElement(*element)) {
@@ skipping 1364 matching lines @@
 }
 
 String Internals::textSurroundingNode(Node* node, int x, int y, unsigned long maxLength)
 {
     blink::WebPoint point(x, y);
     SurroundingText surroundingText(VisiblePosition(node->renderer()->positionForPoint(static_cast<IntPoint>(point))), maxLength);
     return surroundingText.content();
 }
 
 }