Use toElement instead of static_cast<Element*> and static_cast<const Element*>

Source/core/editing/CompositeEditCommand.cpp

Index: Source/core/editing/CompositeEditCommand.cpp
diff --git a/Source/core/editing/CompositeEditCommand.cpp b/Source/core/editing/CompositeEditCommand.cpp
index 11b3ed751abb4ebaf772e9aeeb60c5b7cd6110e7..6490a572a97f4f751addb3fa661613c25b5a6d46 100644
--- a/Source/core/editing/CompositeEditCommand.cpp
+++ b/Source/core/editing/CompositeEditCommand.cpp
@@ -1000,7 +1000,7 @@ void CompositeEditCommand::cloneParagraphUnderNewElement(Position& start, Positi
         for (size_t i = ancestors.size(); i != 0; --i) {
             Node* item = ancestors[i - 1].get();
             RefPtr<Node> child = item->cloneNode(isTableElement(item));
-            appendNode(child, static_cast<Element *>(lastNode.get()));
+            appendNode(child, toElement(lastNode.get()));
             lastNode = child.release();
         }
     }