DefaultSamplingCallback  861 base/debug/trace_event_impl.cc   static void DefaultSamplingCallback(TraceBucketData* bucekt_data);
DefaultSamplingCallback 1361 base/debug/trace_event_impl.cc           Bind(&TraceSamplingThread::DefaultSamplingCallback));
DefaultSamplingCallback 1365 base/debug/trace_event_impl.cc           Bind(&TraceSamplingThread::DefaultSamplingCallback));
DefaultSamplingCallback 1369 base/debug/trace_event_impl.cc           Bind(&TraceSamplingThread::DefaultSamplingCallback));