Use tighter typing in editing: EditingStyle

Source/core/editing/RemoveFormatCommand.cpp

 /*
  * Copyright (C) 2007 Apple Computer, Inc.  All rights reserved.
  * Copyright (C) 2010 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 69 matching lines @@
 
 void RemoveFormatCommand::doApply()
 {
     LocalFrame* frame = document().frame();
 
     if (!frame->selection().selection().isNonOrphanedCaretOrRange())
         return;
 
     // Get the default style for this editable root, it's the style that we'll give the
     // content that we're operating on.
-    Node* root = frame->selection().rootEditableElement();
+    Element* root = frame->selection().rootEditableElement();
     RefPtrWillBeRawPtr<EditingStyle> defaultStyle = EditingStyle::create(root);
 
     // We want to remove everything but transparent background.
     // FIXME: We shouldn't access style().
     defaultStyle->style()->setProperty(CSSPropertyBackgroundColor, CSSValueTransparent);
 
     applyCommandToComposite(ApplyStyleCommand::create(document(), defaultStyle.get(), isElementForRemoveFormatCommand, editingAction()));
 }
 
 }