void* CreateHistogram(
    const char *name, int min, int max, size_t buckets) {
  if (min <= 0)
    min = 1;
  std::string histogram_name;
  RenderThreadImpl* render_thread_impl = RenderThreadImpl::current();
  if (render_thread_impl) {  // Can be null in tests.
    histogram_name = render_thread_impl->
        histogram_customizer()->ConvertToCustomHistogramName(name);
  } else {
    histogram_name = std::string(name);
  }
  base::HistogramBase* histogram = base::Histogram::FactoryGet(
      histogram_name, min, max, buckets,
      base::Histogram::kUmaTargetedHistogramFlag);
  return histogram;
}

The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.