Minimize RenderObject* casting to RenderText*

Source/core/editing/InsertParagraphSeparatorCommand.cpp

 /*
  * Copyright (C) 2005, 2006 Apple Computer, 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 19 matching lines @@
 #include "core/dom/Document.h"
 #include "core/dom/NodeTraversal.h"
 #include "core/dom/Text.h"
 #include "core/editing/EditingStyle.h"
 #include "core/editing/InsertLineBreakCommand.h"
 #include "core/editing/VisibleUnits.h"
 #include "core/editing/htmlediting.h"
 #include "core/html/HTMLBRElement.h"
 #include "core/html/HTMLElement.h"
 #include "core/rendering/RenderObject.h"
+#include "core/rendering/RenderText.h"
 
 namespace blink {
 
 using namespace HTMLNames;
 
 // When inserting a new line, we want to avoid nesting empty divs if we can.  Otherwise, when
 // pasting, it's easy to have each new line be a div deeper than the previous.  E.g., in the case
 // below, we want to insert at ^ instead of |.
 // <div>foo<div>bar</div>|</div>^
 static Element* highestVisuallyEquivalentDivBelowRoot(Element* startBlock)
@@ skipping 377 matching lines @@
 }
 
 void InsertParagraphSeparatorCommand::trace(Visitor *visitor)
 {
     visitor->trace(m_style);
     CompositeEditCommand::trace(visitor);
 }
 
 
 } // namespace blink