Have Range constructor take a Document reference in argument

Source/web/WebRange.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 109 matching lines @@
     Element* selectionRoot = webFrame->selection().rootEditableElement();
     ContainerNode* scope = selectionRoot ? selectionRoot : webFrame->document()->documentElement();
     return TextIterator::rangeFromLocationAndLength(scope, start, length);
 }
 
 WebVector<WebFloatQuad> WebRange::textQuads() const
 {
     if (isNull())
         return WebVector<WebFloatQuad>();
 
-    Frame* frame = m_private->ownerDocument() ? m_private->ownerDocument()->frame() : 0;
+    Frame* frame = m_private->ownerDocument().frame();
     if (!frame)
         return WebVector<WebFloatQuad>();
 
     Vector<FloatQuad> quads;
     m_private->textQuads(quads);
     for (unsigned i = 0; i < quads.size(); ++i) {
         quads[i].setP1(frame->view()->contentsToWindow(roundedIntPoint(quads[i].p1())));
         quads[i].setP2(frame->view()->contentsToWindow(roundedIntPoint(quads[i].p2())));
         quads[i].setP3(frame->view()->contentsToWindow(roundedIntPoint(quads[i].p3())));
         quads[i].setP4(frame->view()->contentsToWindow(roundedIntPoint(quads[i].p4())));
@@ skipping 20 matching lines @@
 
 void WebRange::assign(WebRangePrivate* p)
 {
     // p is already ref'd for us by the caller
     if (m_private)
         m_private->deref();
     m_private = p;
 }
 
 } // namespace WebKit