Bug 1233454 - Guard against ps timeout in devicemanagerADB.getProcessList; r=jmaher

testing/mozbase/mozdevice/mozdevice/devicemanagerADB.py

@@ -323,10 +323,12 @@ class DeviceManagerADB(DeviceManager):
         return data
 
     def getProcessList(self):
+        ret = []
         p = self._runCmd(["shell", "ps"], timeout=self.short_timeout)
+        if not p or not p.output or len(p.output) < 1:
+            return ret
         # first line is the headers
         p.output.pop(0)
-        ret = []
         for proc in p.output:
             els = proc.split()
             # We need to figure out if this is "user pid name" or