Revert of [android] Stop using isolate.py for data dependency management.

build/android/pylib/local/device/local_device_test_run.py

Index: build/android/pylib/local/device/local_device_test_run.py
diff --git a/build/android/pylib/local/device/local_device_test_run.py b/build/android/pylib/local/device/local_device_test_run.py
index fa7ee5db58db2325bdbb0985a452d07db64f62a0..e2343eadc7446e2311464dfc18e8d0faaab68fd3 100644
--- a/build/android/pylib/local/device/local_device_test_run.py
+++ b/build/android/pylib/local/device/local_device_test_run.py
@@ -5,7 +5,6 @@
 import fnmatch
 import imp
 import logging
-import posixpath
 import signal
 import thread
 import threading
@@ -45,15 +44,6 @@ def IncrementalInstall(device, apk_helper, installer_script):
                     permissions=None)  # Auto-grant permissions from manifest.
 
 
-def SubstituteDeviceRoot(device_path, device_root):
-  if not device_path:
-    return device_root
-  elif isinstance(device_path, list):
-    return posixpath.join(*(p if p else device_root for p in device_path))
-  else:
-    return device_path
-
-
 class LocalDeviceTestRun(test_run.TestRun):
 
   def __init__(self, env, test_instance):