simpleperf: fix scripts based on test on darwin/windows.

1. fix inferno.bat to correctly pass arguments.
2. type `inferno.bat` instead of `./inferno.bat`.
3. call `inferno.bat` in python should use shell=True.
4. fix the way to open browser on darwin/windows.

Bug: http://b/64035530
Test: run test.py on all platforms.

Change-Id: I5e22907d0c25186b129bf82e0f83d3b71e28ffb2
5 files changed