Oilpan: put ClientRect(List) on the heap.

Source/core/dom/ClientRectList.idl

 /*
  * Copyright (C) 2009 Apple 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 22 matching lines @@
 // http://dev.w3.org/fxtf/geometry/#DOMRectList
 
 // CSSOM View Module also says: "The DOMRectList interface is at-risk.
 // The authors of this specification await feedback from implementers
 // if the item() function of DOMRectList is currently in use on legacy
 // interfaces. If there is no/not enough content to justify
 // DOMRectList, legacy interfaces must use sequences instead and
 // DOMRectList will be removed from this specification."
 
 [
-    WillBeGarbageCollected,
+    GarbageCollected,
 ] interface ClientRectList {
     readonly attribute unsigned long length;
     [MeasureAs=ClientRectListItem] ClientRect item(unsigned long index);
     getter ClientRect (unsigned long index);
 };