Relands Android perf tests: kill adbd on the device after running a test.

build/android/pylib/perf/test_runner.py

Index: build/android/pylib/perf/test_runner.py
diff --git a/build/android/pylib/perf/test_runner.py b/build/android/pylib/perf/test_runner.py
index e3648f74aafd1d9d5c2f9f415c5512030ecb1cd1..21f1d4916c54c9efaf2b70bc26a249d08bf87d41 100644
--- a/build/android/pylib/perf/test_runner.py
+++ b/build/android/pylib/perf/test_runner.py
@@ -48,6 +48,7 @@ import pickle
 import sys
 
 from pylib import constants
+from pylib import forwarder
 from pylib import pexpect
 from pylib.base import base_test_result
 from pylib.base import base_test_runner
@@ -121,6 +122,13 @@ class TestRunner(base_test_runner.BaseTestRunner):
     Returns:
       A tuple containing (Output, base_test_result.ResultType)
     """
+    try:
+      logging.warning('Unmapping device ports')
+      forwarder.Forwarder.UnmapAllDevicePorts(self.adb)
+      self.adb.RestartAdbdOnDevice()
+    except Exception as e:
+      logging.error('Exception when tearing down device %s', e)
+
     cmd = ('%s --device %s' %
            (self._tests[test_name], self.device))
     logging.info('%s : %s', test_name, cmd)