SIZE huge. objects that can entrain just about anything.

       nsDocShell
       nsDocument
       nsGlobalWindow

SIZE medium. when known to leak, allowed to entrain unknown objects.

       nsGenericElement
  LEAK nsRDFResource                   # bug 584590
  LEAK BackstagePass                   # bug 584590, bug 397206
  LEAK nsDNSService                    # Bug 102229 or bug 419562
  LEAK nsJVMManager                    # Bug 417630 and friends
  LEAK nsSimpleNestedURI               # Bug 403199
  LEAK nsHTMLDNSPrefetch::nsDeferrals  # Bug 463724
  LEAK nsDNSPrefetch                   # Bug 463724
  LEAK nsDNSAsyncRequest               # Bug 463724
  LEAK nsHostResolver                  # Bug 463724
  LEAK StartupCacheListener            # Bug 601341

SIZE tiny. objects that should never entrain others. (last group is also the default for unknown objects)

  LEAK nsTArray_base                   # Bug 603844, bug 610094 (negative)
  LEAK nsStringBuffer                  # Bug 603844