Bug 1355540, use SegmentedVector for pending links to avoid slow hashtable lookups in hot codepaths, r=bz

dom/html/HTMLAreaElement.cpp

@@ -142,13 +142,6 @@ HTMLAreaElement::UnbindFromTree(bool aDeep, bool aNullParent)
   // be under a different xml:base, so forget the cached state now.
   Link::ResetLinkState(false, Link::ElementHasHref());
 
-  // Note, we need to use OwnerDoc() here, since GetComposedDoc() might
-  // return null.
-  nsIDocument* doc = OwnerDoc();
-  if (doc) {
-    doc->UnregisterPendingLinkUpdate(this);
-  }
-
   nsGenericHTMLElement::UnbindFromTree(aDeep, aNullParent);
 }