Step 7. perform_systrace fails

[SztoDwa]

On my windows 7 installation the script fails at executing line 79 of the run_perf_tests.py . The reason is: os_error global is not defined. I tried to modify that on my own, by changing from except OSError: print 'ERROR executing systrace ' + os_error to except OSError as err: print 'ERROR executing systrace ' + err.strerror but monkeyrunner rejects that - it doesn't allow the "as" functionality for handling exceptions.

I know that this line's purpose is just to tell me what went wrong when trying to run the systrace command, but I'll never learn that if I don't get this line of script fixed.