smssender/smsdemo/adb/systrace/catapult/common/py_trace_event

py_trace_event allows low-overhead instrumentation of a multi-threaded,
multi-process application in order to study its global performance
characteristics. It uses the trace event format used in Chromium/Chrome's
about:tracing system.

Trace files generated by py_trace_event can be viewed and manipulated by
trace_event_viewer.