Introduce toHTMLInputElement(Node*), and use it.

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 1228 matching lines @@
     // A br that was originally acting as a line break should still be acting as a line break, not as a placeholder.
     return isStartOfParagraph(visiblePos) && isEndOfParagraph(visiblePos);
 }
 
 bool ReplaceSelectionCommand::shouldPerformSmartReplace() const
 {
     if (!m_smartReplace)
         return false;
 
     Element* textControl = enclosingTextFormControl(positionAtStartOfInsertedContent().deepEquivalent());
-    if (textControl && textControl->hasTagName(inputTag) && static_cast<HTMLInputElement*>(textControl)->isPasswordField())
+    if (textControl && textControl->hasTagName(inputTag) && toHTMLInputElement(textControl)->isPasswordField())
         return false; // Disable smart replace for password fields.
 
     return true;
 }
 
 static bool isCharacterSmartReplaceExemptConsideringNonBreakingSpace(UChar32 character, bool previousCharacter)
 {
     return isCharacterSmartReplaceExempt(character == noBreakSpace ? ' ' : character, previousCharacter);
 }
 
@@ skipping 225 matching lines @@
         removeNodeAndPruneAncestors(nodeAfterInsertionPos.get());
 
     VisibleSelection selectionAfterReplace(m_selectReplacement ? start : end, end);
 
     setEndingSelection(selectionAfterReplace);
 
     return true;
 }
 
 } // namespace WebCore