Hello sparky :)
Should I make android environment for solving this issue? 
I'm having difficulty to making android environment. So, I need a little time.
I checked right connection status through
adb devices command and ran command
./mach raptor --test raptor-speedometer --app=geckoview --binary="org.mozilla.geckoview_example"
to run test.
But, An error has occurred.
03:37:13 ERROR - File "/home/mj/work/mozilla/mozilla-central/testing/mozbase/mozdevice/mozdevice/adb.py", line 207, in __init__ 03:37:13 ERROR - raise ADBError('%s: %s is not executable.' % (exc, adb)) 03:37:13 ERROR - ADBError: [Errno 2] No such file or directory: adb is not executable.
GeckoView Eample was installed on my android phone but connection failed for running raptor.
Can I get some advice for the connection?
And, The document contains the following:
Next, make sure your Android device is ready to go. Local Android-device prerequisites are: Device is rooted
Is this where I need?
There is a link, but I have a permission.
Let me know if there's anything else I need to know more.
If I don't go well, I'll try to install it again.
 Running on the Android GeckoView Example App part