Lazily generate HistoryItem's serialized form state

Source/web/WebFrameImpl.cpp

 /*
  * Copyright (C) 2009 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 987 matching lines @@
     return WebHistoryItem(frame()->page()->historyController().previousItemForExport());
 }
 
 WebHistoryItem WebFrameImpl::currentHistoryItem() const
 {
     ASSERT(frame());
 
     // We're shutting down.
     if (!frame()->loader().documentLoader())
         return WebHistoryItem();
-
-    // Lazily update the document state if it was dirtied. Doing it here
-    // avoids synchronously serializing forms as they're changing.
-    frame()->loader().saveDocumentState();

[Nate Chapin, 2014/04/17 21:16:25]

This whole function is already dead as a result of moving history state to
content/renderer.

This call to saveDocumentState() was kind of important for not randomly dropping
form state, hence my timing in writing this patch :)

-
     return WebHistoryItem(frame()->page()->historyController().currentItemForExport());
 }
 
 void WebFrameImpl::enableViewSourceMode(bool enable)
 {
     if (frame())
         frame()->setInViewSourceMode(enable);
 }
 
 bool WebFrameImpl::isViewSourceModeEnabled() const
@@ skipping 966 matching lines @@
 
 void WebFrameImpl::invalidateAll() const
 {
     ASSERT(frame() && frame()->view());
     FrameView* view = frame()->view();
     view->invalidateRect(view->frameRect());
     invalidateScrollbar();
 }
 
 } // namespace blink