Move CSSOM classes to using MutableStylePropertySet over StylePropertySet.

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 1884 matching lines @@
     if (caretBrowsing)
         m_frame->page()->focusController()->setFocusedNode(0, m_frame);
 }
 
 void DragCaretController::paintDragCaret(Frame* frame, GraphicsContext* p, const LayoutPoint& paintOffset, const LayoutRect& clipRect) const
 {
     if (m_position.deepEquivalent().deprecatedNode()->document()->frame() == frame)
         paintCaret(m_position.deepEquivalent().deprecatedNode(), p, paintOffset, clipRect);
 }
 
-PassRefPtr<StylePropertySet> FrameSelection::copyTypingStyle() const
+PassRefPtr<MutableStylePropertySet> FrameSelection::copyTypingStyle() const
 {
     if (!m_typingStyle || !m_typingStyle->style())
         return 0;
     return m_typingStyle->style()->mutableCopy();
 }
 
 bool FrameSelection::shouldDeleteSelection(const VisibleSelection& selection) const
 {
     return m_frame->editor()->client()->shouldDeleteRange(selection.toNormalizedRange().get());
 }
@@ skipping 155 matching lines @@
     sel.showTreeForThis();
 }
 
 void showTree(const WebCore::FrameSelection* sel)
 {
     if (sel)
         sel->showTreeForThis();
 }
 
 #endif