tools/android/loading Fix import issues in webserver unittests

tools/android/loading/trace_test/webserver_unittest.py

Index: tools/android/loading/trace_test/webserver_unittest.py
diff --git a/tools/android/loading/trace_test/webserver_unittest.py b/tools/android/loading/trace_test/webserver_unittest.py
index 2716492e7059b99e407dbf7cd1976efaad16796d..35fcb4d4df91edb55a2da20ed0fcf9ecba484c48 100644
--- a/tools/android/loading/trace_test/webserver_unittest.py
+++ b/tools/android/loading/trace_test/webserver_unittest.py
@@ -8,7 +8,7 @@ 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
@@ -48,3 +48,7 @@ class TracingTrackTestCase(unittest.TestCase):
 
       sock.close()
       self.assertTrue(server.Stop())
+
+
+if __name__ == '__main__':
+  unittest.main()