title: Running systrace gives "preexec_fn is not supported on Windows" error
body: <p>I'm trying to use Android's Systrace feature as described <a href="https://developer.android.com/studio/profile/systrace.html" rel="noreferrer">here</a> and <a href="https://developer.android.com/studio/profile/systrace-commandline.html#options-4.3" rel="noreferrer">here</a> but when I run the command line described in the above links, it gives me this error :</p>
  
  <pre><code>File "C:\Python27\lib\subprocess.py", line 664, in __init__
  raise ValueError("preexec_fn is not supported on Windows "
  ValueError: preexec_fn is not supported on Windows platforms
  </code></pre>
  
  <p>The command line described above is : </p>
  
  <pre><code>python systrace.py --time=10 -o mynewtrace.html sched gfx view wm
  </code></pre>
  
  <p>I'm not a python dev so I don't have any clue about it and google doesn't help me a lot, any idea?</p>
  
  <p>-- I'm running on a windows 10 computer.</p>