Have Frame::tree() return a reference

Source/core/page/Settings.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2011, 2012 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 26 matching lines @@
 #include "core/page/Page.h"
 #include "core/platform/ScrollbarTheme.h"
 #include "core/rendering/TextAutosizer.h"
 
 using namespace std;
 
 namespace WebCore {
 
 static void setImageLoadingSettings(Page* page)
 {
-    for (Frame* frame = page->mainFrame(); frame; frame = frame->tree()->traverseNext()) {
+    for (Frame* frame = page->mainFrame(); frame; frame = frame->tree().traverseNext()) {
         frame->document()->fetcher()->setImagesEnabled(page->settings().areImagesEnabled());
         frame->document()->fetcher()->setAutoLoadImages(page->settings().loadsImagesAutomatically());
     }
 }
 
 // Sets the entry in the font map for the given script. If family is the empty string, removes the entry instead.
 static inline void setGenericFontFamilyMap(ScriptFontFamilyMap& fontMap, const AtomicString& family, UScriptCode script, Page* page)
 {
     ScriptFontFamilyMap::iterator it = fontMap.find(static_cast<int>(script));
     if (family.isEmpty()) {
@@ skipping 198 matching lines @@
     m_loadWithOverviewMode = loadWithOverviewMode;
     if (m_page->mainFrame())
         m_page->chrome().dispatchViewportPropertiesDidChange(m_page->mainFrame()->document()->viewportDescription());
 }
 
 void Settings::setTextAutosizingFontScaleFactor(float fontScaleFactor)
 {
     m_textAutosizingFontScaleFactor = fontScaleFactor;
 
     // FIXME: I wonder if this needs to traverse frames like in WebViewImpl::resize, or whether there is only one document per Settings instance?
-    for (Frame* frame = m_page->mainFrame(); frame; frame = frame->tree()->traverseNext())
+    for (Frame* frame = m_page->mainFrame(); frame; frame = frame->tree().traverseNext())
         frame->document()->textAutosizer()->recalculateMultipliers();
 
     m_page->setNeedsRecalcStyleInAllFrames();
 }
 
 void Settings::setMediaTypeOverride(const String& mediaTypeOverride)
 {
     if (m_mediaTypeOverride == mediaTypeOverride)
         return;
 
@@ skipping 109 matching lines @@
 {
     if (m_viewportEnabled == enabled)
         return;
 
     m_viewportEnabled = enabled;
     if (m_page->mainFrame())
         m_page->mainFrame()->document()->updateViewportDescription();
 }
 
 } // namespace WebCore