Have Frame::script() return a reference

Source/core/frame/Frame.cpp

 /*
  * Copyright (C) 1998, 1999 Torben Weis <weis@kde.org>
  *                     1999 Lars Knoll <knoll@kde.org>
  *                     1999 Antti Koivisto <koivisto@kde.org>
  *                     2000 Simon Hausmann <hausmann@kde.org>
  *                     2000 Stefan Schimanski <1Stein@gmx.de>
  *                     2001 George Staikos <staikos@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2005 Alexey Proskuryakov <ap@nypop.com>
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
@@ skipping 319 matching lines @@
         (*it)->willDetachPage();
 
     // FIXME: It's unclear as to why this is called more than once, but it is,
     // so page() could be NULL.
     if (page() && page()->focusController().focusedFrame() == this)
         page()->focusController().setFocusedFrame(0);
 
     if (page() && page()->scrollingCoordinator() && m_view)
         page()->scrollingCoordinator()->willDestroyScrollableArea(m_view.get());
 
-    script()->clearScriptObjects();
+    script().clearScriptObjects();
 }
 
 void Frame::detachFromPage()
 {
     // We should never be detatching the page during a Layout.
     RELEASE_ASSERT(!m_view || !m_view->isInLayout());
     m_page = 0;
 }
 
 void Frame::disconnectOwnerElement()
@@ skipping 326 matching lines @@
     if (!m_page)
         return 0;
 
     double ratio = m_page->deviceScaleFactor();
     if (RuntimeEnabledFeatures::devicePixelRatioIncludesZoomEnabled())
         ratio *= pageZoomFactor();
     return ratio;
 }
 
 } // namespace WebCore