Lazily generate HistoryItem's serialized form state

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 703 matching lines @@
     return mainItem->documentState();
 }
 
 void Internals::setFormControlStateOfHistoryItem(const Vector<String>& state, ExceptionState& exceptionState)
 {
     HistoryItem* mainItem = frame()->loader().currentItem();
     if (!mainItem) {
         exceptionState.throwDOMException(InvalidAccessError, "No history item is available.");
         return;
     }
+    mainItem->clearDocumentState();
     mainItem->setDocumentState(state);
 }
 
 void Internals::setEnableMockPagePopup(bool enabled, ExceptionState& exceptionState)
 {
     Document* document = contextDocument();
     if (!document || !document->page())
         return;
     Page* page = document->page();
     if (!enabled) {
@@ skipping 1320 matching lines @@
     return MallocStatistics::create();
 }
 
 PassRefPtrWillBeRawPtr<TypeConversions> Internals::typeConversions() const
 {
     return TypeConversions::create();
 }
 
 Vector<String> Internals::getReferencedFilePaths() const
 {
-    frame()->loader().saveDocumentState();
-    return FormController::getReferencedFilePaths(frame()->loader().currentItem()->documentState());
+    return frame()->loader().currentItem()->getReferencedFilePaths();
 }
 
 void Internals::startTrackingRepaints(Document* document, ExceptionState& exceptionState)
 {
     if (!document || !document->view()) {
         exceptionState.throwDOMException(InvalidAccessError, document ? "The document's view cannot be retrieved." : "The document provided is invalid.");
         return;
     }
 
     FrameView* frameView = document->view();
@@ skipping 355 matching lines @@
 String Internals::textSurroundingNode(Node* node, int x, int y, unsigned long maxLength)
 {
     if (!node)
         return String();
     blink::WebPoint point(x, y);
     SurroundingText surroundingText(VisiblePosition(node->renderer()->positionForPoint(static_cast<IntPoint>(point))), maxLength);
     return surroundingText.content();
 }
 
 }