Revert of [Android] Clean up old_interface in build/android/.

build/android/pylib/base/base_test_runner.py

Index: build/android/pylib/base/base_test_runner.py
diff --git a/build/android/pylib/base/base_test_runner.py b/build/android/pylib/base/base_test_runner.py
index 1ca033834c4d446bb2b655de12573fae54fe522b..4e2eae70427c4d967d7081bf3afe6a92739edd0a 100644
--- a/build/android/pylib/base/base_test_runner.py
+++ b/build/android/pylib/base/base_test_runner.py
@@ -26,11 +26,12 @@
 class BaseTestRunner(object):
   """Base class for running tests on a single device."""
 
-  def __init__(self, device_serial, tool):
+  def __init__(self, device_serial, tool, cleanup_test_files=False):
     """
       Args:
         device: Tests will run on the device of this ID.
         tool: Name of the Valgrind tool.
+        cleanup_test_files: Whether or not to cleanup test files on device.
     """
     self.device_serial = device_serial
     self.device = device_utils.DeviceUtils(device_serial)
@@ -44,6 +45,7 @@
     # starting it in TestServerThread.
     self.test_server_spawner_port = 0
     self.test_server_port = 0
+    self._cleanup_test_files = cleanup_test_files
 
   def _PushTestServerPortInfoToDevice(self):
     """Pushes the latest port information to device."""
@@ -75,6 +77,8 @@
   def TearDown(self):
     """Run once after all tests are run."""
     self.ShutdownHelperToolsForTestSuite()
+    if self._cleanup_test_files:
+      self.device.old_interface.RemovePushedFiles()
 
   def LaunchTestHttpServer(self, document_root, port=None,
                            extra_config_contents=None):