Remove some unused variable assignments

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 @@
     if (lastLeafInserted && lastLeafInserted->isTextNode() && !nodeHasVisibleRenderText(toText(lastLeafInserted))
         && !enclosingNodeWithTag(firstPositionInOrBeforeNode(lastLeafInserted), selectTag)
         && !enclosingNodeWithTag(firstPositionInOrBeforeNode(lastLeafInserted), scriptTag)) {
         insertedNodes.willRemoveNode(lastLeafInserted);
         removeNode(lastLeafInserted);
     }
 
     // We don't have to make sure that firstNodeInserted isn't inside a select or script element, because
     // it is a top level node in the fragment and the user can't insert into those elements.
     Node* firstNodeInserted = insertedNodes.firstNodeInserted();
-    lastLeafInserted = insertedNodes.lastLeafInserted();
     if (firstNodeInserted && firstNodeInserted->isTextNode() && !nodeHasVisibleRenderText(toText(firstNodeInserted))) {
         insertedNodes.willRemoveNode(firstNodeInserted);
         removeNode(firstNodeInserted);
     }
 }
 
 VisiblePosition ReplaceSelectionCommand::positionAtEndOfInsertedContent() const
 {
     // FIXME: Why is this hack here?  What's special about <select> tags?
     Node* enclosingSelect = enclosingNodeWithTag(m_endOfInsertedContent, selectTag);
@@ skipping 796 matching lines @@
         removeNodeAndPruneAncestors(nodeAfterInsertionPos.get());
 
     VisibleSelection selectionAfterReplace(m_selectReplacement ? start : end, end);
 
     setEndingSelection(selectionAfterReplace);
 
     return true;
 }
 
 } // namespace WebCore