Use new is*Element() helper functions more in core/ code

Source/core/frame/SmartClip.cpp

 /*
  * Copyright (C) 2013 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 203 matching lines @@
     }
 
     return minNode;
 }
 
 // This function appears to heuristically guess whether to include a background
 // image in the smart clip. It seems to want to include sprites created from
 // CSS background images but to skip actual backgrounds.
 bool SmartClip::shouldSkipBackgroundImage(Node* node)
 {
+    ASSERT(node);
     // Apparently we're only interested in background images on spans and divs.
-    if (!node->hasTagName(HTMLNames::spanTag) && !node->hasTagName(HTMLNames::divTag))
+    if (!isHTMLSpanElement(*node) && !isHTMLDivElement(*node))
         return true;
 
     // This check actually makes a bit of sense. If you're going to sprite an
     // image out of a CSS background, you're probably going to specify a height
     // or a width. On the other hand, if we've got a legit background image,
     // it's very likely the height or the width will be set to auto.
     RenderObject* renderer = node->renderer();
     if (renderer && (renderer->style()->logicalHeight().isAuto() || renderer->style()->logicalWidth().isAuto()))
         return true;
 
@@ skipping 50 matching lines @@
 
                 result.append(nodeValue);
             }
         }
     }
 
     return result.toString();
 }
 
 } // namespace WebCore