Android: further "user build" perf test automation.

build/android/pylib/android_commands.py

Index: build/android/pylib/android_commands.py
diff --git a/build/android/pylib/android_commands.py b/build/android/pylib/android_commands.py
index 4c3c6fe65b58e1491003dd13d7b1a462df9cd992..a4340b2a5d64384e881b52f5c7c3547e18e68c44 100644
--- a/build/android/pylib/android_commands.py
+++ b/build/android/pylib/android_commands.py
@@ -729,7 +729,7 @@ class AndroidCommands(object):
     Devices running user builds don't have adb root, but may provide "su" which
     can be used for accessing protected files.
     """
-    return self.RunShellCommand('su -c echo') == ['']
+    return self.RunShellCommand('su -c cat /dev/null') == ['']

[Sami, 2013/02/13 11:05:34]

This could be slightly more reliable if we tried to cat a file that was only
readable by root (e.g., /proc/kmsg). But let's not make this any more complex
than it needs to be :)

[bulach, 2013/02/13 11:08:57]

:)

 
   def GetProtectedFileContents(self, filename, log_result=False):
     """Gets contents from the protected file specified by |filename|.