Add option to output device status data in format for dashboard.

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 48116b88ffd8e7e7a889ea679ff99e55569e702c..35e0ebda7e9aeed6fe15cf7f52a5d0226ecbd60c 100644
--- a/build/android/pylib/android_commands.py
+++ b/build/android/pylib/android_commands.py
@@ -114,7 +114,18 @@ def GetAttachedDevices():
   return devices
 
 
+def GetAttachedOfflineDevices():
+  """Returns a list of attached, offline android devices.
+
+  Returns: List of devices with status 'offline'.
+  """
+  re_device = re.compile('^([a-zA-Z0-9_:.-]+)\toffline$', re.MULTILINE)
+  return re_device.findall(cmd_helper.GetCmdOutput([constants.ADB_PATH,
+                                                    'devices']))
+
+
 def IsDeviceAttached(device):
+  """Return true if the device is attached and online."""
   return device in GetAttachedDevices()