TraceSampleCallback  844 base/debug/trace_event_impl.cc                   TraceSampleCallback callback);
TraceSampleCallback  849 base/debug/trace_event_impl.cc   TraceSampleCallback callback;
TraceSampleCallback  874 base/debug/trace_event_impl.cc                             TraceSampleCallback callback);
TraceSampleCallback  933 base/debug/trace_event_impl.cc     TraceSampleCallback callback) {
TraceSampleCallback  959 base/debug/trace_event_impl.cc                                  TraceSampleCallback callback)