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

build/android/pylib/android_commands.py

Index: build/android/pylib/android_commands.py
diff --git a/build/android/pylib/android_commands.py b/build/android/pylib/android_commands.py
index 20684b7b07b317b870370d8476eb237f6cbffe23..c1f25eb200add21cc388b7fe5d7fac328bfc9576 100644
--- a/build/android/pylib/android_commands.py
+++ b/build/android/pylib/android_commands.py
@@ -458,6 +458,14 @@ class AndroidCommands(object):
     if out.strip() != 'remount succeeded':
       raise errors.MsgException('Remount failed: %s' % out)
 
+  def RestartAdbdOnDevice(self):
+    logging.info('Killing adbd on the device...')
+    adb_pids = self.ExtractPid('adbd')
+    if adb_pids:
+      self.RunShellCommandWithSU('kill %s' % ' '.join(adb_pids))
+    logging.info('Waiting for device to settle...')
+    self._adb.SendCommand('wait-for-device')
+
   def RestartAdbServer(self):
     """Restart the adb server."""
     ret = self.KillAdbServer()