I started my emulator with ./emulator -trace profile -avd emulator_15.  I then tracked down the trace files to ~/.android/avd/rodgers_emulator_15.avd/traces/profile, where there are six files:  qtrace.bb, qtrace.exc, qtrace.insn, qtrace.method, qtrace.pid, qtrace.static.  I can't figure out what to do with these files.  I've tried both dmtracedump and traceview on all of the files, but none seem to generate any output I can do anything with.
How can I view the proportion of time taken by native method calls on Android?