Minimize RenderObject* casting to RenderText*

Source/core/editing/ReplaceSelectionCommand.cpp

 /*
  * Copyright (C) 2005, 2006, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2009, 2010, 2011 Google 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
@@ skipping 657 matching lines @@
         RefPtrWillBeRawPtr<Node> nodeToSplitTo = splitTreeToNode(node.get(), ancestor.get(), true);
         removeNode(node);
         insertNodeBefore(node, nodeToSplitTo);
     }
     if (!ancestor->firstChild())
         removeNode(ancestor.release());
 }
 
 static inline bool nodeHasVisibleRenderText(Text& text)
 {
-    return text.renderer() && toRenderText(text.renderer())->renderedTextLength() > 0;
+    return text.renderer() && text.renderer()->renderedTextLength() > 0;
 }
 
 void ReplaceSelectionCommand::removeUnrenderedTextNodesAtEnds(InsertedNodes& insertedNodes)
 {
     document().updateLayoutIgnorePendingStylesheets();
 
     Node* lastLeafInserted = insertedNodes.lastLeafInserted();
     if (lastLeafInserted && lastLeafInserted->isTextNode() && !nodeHasVisibleRenderText(toText(*lastLeafInserted))
         && !enclosingElementWithTag(firstPositionInOrBeforeNode(lastLeafInserted), selectTag)
         && !enclosingElementWithTag(firstPositionInOrBeforeNode(lastLeafInserted), scriptTag)) {
@@ skipping 841 matching lines @@
 void ReplaceSelectionCommand::trace(Visitor* visitor)
 {
     visitor->trace(m_startOfInsertedContent);
     visitor->trace(m_endOfInsertedContent);
     visitor->trace(m_insertionStyle);
     visitor->trace(m_documentFragment);
     CompositeEditCommand::trace(visitor);
 }
 
 } // namespace blink