Have Node::document() return a reference instead of a pointer

Source/core/editing/FrameSelection.cpp

 /*
  * Copyright (C) 2004, 2008, 2009, 2010 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.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 223 matching lines @@
         s.setIsDirectional(true);
 
     if (!m_frame) {
         m_selection = s;
         return;
     }
 
     // <http://bugs.webkit.org/show_bug.cgi?id=23464>: Infinite recursion at FrameSelection::setSelection
     // if document->frame() == m_frame we can get into an infinite loop
     if (s.base().anchorNode()) {
-        Document* document = s.base().anchorNode()->document();
-        if (document->frame() && document->frame() != m_frame && document != m_frame->document()) {
-            RefPtr<Frame> guard = document->frame();
-            document->frame()->selection()->setSelection(s, options, align, granularity);
+        Document& document = s.base().anchorNode()->document();
+        if (document.frame() && document.frame() != m_frame && &document != m_frame->document()) {
+            RefPtr<Frame> guard = document.frame();
+            document.frame()->selection()->setSelection(s, options, align, granularity);
             // It's possible that during the above set selection, this FrameSelection has been modified by
             // selectFrameElementInParentIfFullySelected, but that the selection is no longer valid since
             // the frame is about to be destroyed. If this is the case, clear our selection.
             if (guard->hasOneRef() && !m_selection.isNonOrphanedCaretOrRange())
                 clear();
             return;
         }
     }
 
     m_granularity = granularity;
@@ skipping 55 matching lines @@
 
     if (!node->isElementNode())
         return false;
 
     Element* element = toElement(node);
     return element->containsIncludingShadowDOM(position.anchorNode());
 }
 
 static void clearRenderViewSelection(const Position& position)
 {
-    RefPtr<Document> document = position.anchorNode()->document();
+    RefPtr<Document> document = &position.anchorNode()->document();
     document->updateStyleIfNeeded();
     if (RenderView* view = document->renderView())
         view->clearSelection();
 }
 
 void FrameSelection::nodeWillBeRemoved(Node* node)
 {
     // There can't be a selection inside a fragment, so if a fragment's node is being removed,
     // the selection in the document that created the fragment needs no adjustment.
     if (isNone() || (node && !node->inDocument()))
@@ skipping 774 matching lines @@
         pos = m_selection.end();
         break;
     case BASE:
         pos = m_selection.base();
         break;
     case EXTENT:
         pos = m_selection.extent();
         break;
     }
 
-    Frame* frame = pos.anchorNode()->document()->frame();
+    Frame* frame = pos.anchorNode()->document().frame();
     if (!frame)
         return x;
 
     if (m_xPosForVerticalArrowNavigation == NoXPosForVerticalArrowNavigation()) {
         VisiblePosition visiblePosition(pos, m_selection.affinity());
         // VisiblePosition creation can fail here if a node containing the selection becomes visibility:hidden
         // after the selection is created and before this function is called.
         x = visiblePosition.isNotNull() ? visiblePosition.lineDirectionPointForBlockDirectionNavigation() : 0;
         m_xPosForVerticalArrowNavigation = x;
     } else
@@ skipping 325 matching lines @@
         setSelection(newSelection);
 
     selectFrameElementInParentIfFullySelected();
     notifyRendererOfSelectionChange(UserTriggered);
 }
 
 bool FrameSelection::setSelectedRange(Range* range, EAffinity affinity, bool closeTyping)
 {
     if (!range || !range->startContainer() || !range->endContainer())
         return false;
-    ASSERT(range->startContainer()->document() == range->endContainer()->document());
+    ASSERT(&range->startContainer()->document() == &range->endContainer()->document());
 
     m_frame->document()->updateLayoutIgnorePendingStylesheets();
 
     // Non-collapsed ranges are not allowed to start at the end of a line that is wrapped,
     // they start at the beginning of the next line instead
     TrackExceptionState es;
     bool collapsed = range->collapsed(es);
     if (es.hadException())
         return false;
 
@@ skipping 182 matching lines @@
     if (!caretIsVisible() || !isCaret())
         return false;
 
     if (m_frame->settings() && m_frame->settings()->caretBrowsingEnabled())
         return false;
 
     Node* root = rootEditableElement();
     if (!root)
         return false;
 
-    Element* focusedElement = root->document()->focusedElement();
+    Element* focusedElement = root->document().focusedElement();
     if (!focusedElement)
         return false;
 
     return focusedElement->containsIncludingShadowDOM(m_selection.start().anchorNode());
 }
 
 void FrameSelection::caretBlinkTimerFired(Timer<FrameSelection>*)
 {
     ASSERT(caretIsVisible());
     ASSERT(isCaret());
@@ skipping 253 matching lines @@
     sel.showTreeForThis();
 }
 
 void showTree(const WebCore::FrameSelection* sel)
 {
     if (sel)
         sel->showTreeForThis();
 }
 
 #endif