void AllocationProfiler::iterate_since_last_gc() {

  {- -------------------------------------------
  (1) GenCollectedHeap::object_iterate_since_last_GC() を呼び出すだけ
      (使用する Closure は AllocProfClosure).
      ---------------------------------------- -}

      if (is_active()) {
        AllocProfClosure blk;
        GenCollectedHeap* heap = GenCollectedHeap::heap();
        heap->object_iterate_since_last_GC(&blk);
      }
    }