Revert "Simplify SVGSVGElement::getElementById method"

Source/core/svg/SVGSVGElement.cpp

 /*
  * Copyright (C) 2004, 2005, 2006 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2010 Rob Buis <buis@kde.org>
  * Copyright (C) 2007 Apple Inc. All rights reserved.
  * Copyright (C) 2014 Google, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 801 matching lines @@
     if (viewElement->hasAttribute(SVGNames::zoomAndPanAttr))
         view->setZoomAndPan(viewElement->zoomAndPan());
     else
         view->setZoomAndPan(zoomAndPan());
 }
 
 // getElementById on SVGSVGElement is restricted to only the child subtree defined by the <svg> element.
 // See http://www.w3.org/TR/SVG11/struct.html#InterfaceSVGSVGElement
 Element* SVGSVGElement::getElementById(const AtomicString& id) const
 {
-    if (!treeScope().containsMultipleElementsWithId(id)) {
-        Element* element = treeScope().getElementById(id);
-        if (!element || !element->isDescendantOf(this))
-            return 0;
+    Element* element = treeScope().getElementById(id);
+    if (element && element->isDescendantOf(this))
+        return element;
 
-        return element;
+    // Fall back to traversing our subtree. Duplicate ids are allowed, the first found will
+    // be returned.
+    for (Node* node = firstChild(); node; node = NodeTraversal::next(*node, this)) {

[Inactive, 2014/03/13 18:11:36]

We may want to use ElementTraversal API in a follow up to make the code a bit
simpler.

+        if (!node->isElementNode())
+            continue;
+
+        Element* element = toElement(node);
+        if (element->getIdAttribute() == id)
+            return element;
     }
-
-    // If duplicate IDs are there, return the first descendant of the svg element.
-    const Vector<Element*>& elements = treeScope().getAllElementsById(id);
-    Vector<Element*>::const_iterator end = elements.end();
-    for (Vector<Element*>::const_iterator it = elements.begin(); it != end; ++it) {
-        if ((*it)->isDescendantOf(this))
-            return *it;
-    }
-
     return 0;
 }
 
 }