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

Source/core/page/DragController.cpp

 /*
  * Copyright (C) 2007, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Google Inc.
  *
  * 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 285 matching lines @@
     m_documentIsHandlingDrag = tryDocumentDrag(dragData, m_dragDestinationAction, dragSession);
     if (!m_documentIsHandlingDrag && (m_dragDestinationAction & DragDestinationActionLoad))
         dragSession.operation = operationForLoad(dragData);
     return dragSession;
 }
 
 static HTMLInputElement* asFileInput(Node* node)
 {
     ASSERT(node);
     for (; node; node = node->shadowHost()) {
-        if (node->hasTagName(HTMLNames::inputTag) && toHTMLInputElement(node)->isFileUpload())
+        if (isHTMLInputElement(*node) && toHTMLInputElement(node)->isFileUpload())
             return toHTMLInputElement(node);
     }
     return 0;
 }
 
 // This can return null if an empty document is loaded.
 static Element* elementUnderMouse(Document* documentUnderMouse, const IntPoint& p)
 {
     LocalFrame* frame = documentUnderMouse->frame();
     float zoomFactor = frame ? frame->pageZoomFactor() : 1;
@@ skipping 331 matching lines @@
             if (dragMode == DRAG_NONE)
                 continue;
             // Even if the image is part of a selection, we always only drag the image in this case.
             if (renderer->isImage()
                 && src->settings()
                 && src->settings()->loadsImagesAutomatically()) {
                 dragType = DragSourceActionImage;
                 return node;
             }
             // Other draggable elements are considered unselectable.
-            if (node->hasTagName(HTMLNames::aTag) && toHTMLAnchorElement(node)->isLiveLink()) {
+            if (isHTMLAnchorElement(*node) && toHTMLAnchorElement(node)->isLiveLink()) {
                 candidateDragType = DragSourceActionLink;
                 break;
             }
             if (dragMode == DRAG_ELEMENT) {
                 candidateDragType = DragSourceActionDHTML;
                 break;
             }
         }
     }
 
@@ skipping 290 matching lines @@
     return keyState & PlatformEvent::CtrlKey;
 #endif
 }
 
 void DragController::cleanupAfterSystemDrag()
 {
 }
 
 } // namespace WebCore