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 3ca868ee6d727b66d8aeb0a6d728c5c43f91f35e..a0a7c8d9a76b85166f3065107b230ecaa4e25875 100644
--- a/build/android/pylib/perf/test_runner.py
+++ b/build/android/pylib/perf/test_runner.py
@@ -57,6 +57,7 @@ import pickle
 import os
 import sys
 
+from pylib import android_commands
 from pylib import constants
 from pylib.base import base_test_result
 from pylib.base import base_test_runner
@@ -157,6 +158,8 @@ class TestRunner(base_test_runner.BaseTestRunner):
     }
     self._SaveResult(persisted_result)
 
+    self.adb.KillAdbdDevice()
+
     return (output, result_type)
 
   def RunTest(self, test_name):