tools/android/loading Fix import issues in webserver unittests

tools/android/loading/trace_test/webserver_unittest.py

 # Copyright 2016 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import os
 import socket
 import sys
 import unittest
 
 _SRC_DIR = os.path.abspath(os.path.join(
-    os.path.dirname(__file__), '..', '..', '..'))
+    os.path.dirname(__file__), '..', '..', '..', '..'))
 sys.path.append(os.path.join(_SRC_DIR, 'tools', 'android', 'loading'))
 
 import options
 from trace_test import webserver_test
 
 
 OPTIONS = options.OPTIONS
 
 
 class TracingTrackTestCase(unittest.TestCase):
@@ skipping 19 matching lines @@
 
       sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
       sock.connect((host, int(port)))
       sock.sendall('GET test.html HTTP/1.1\n\n')
       data = sock.recv(4096)
       print '%%% ' + data
       self.assertTrue('HTTP/1.0 200 OK' in data)
 
       sock.close()
       self.assertTrue(server.Stop())
+
+
+if __name__ == '__main__':
+  unittest.main()