mojo: Add RunLoop::Current() and refactor unit tests.

mojo/python/tests/messaging_unittest.py

Index: mojo/python/tests/messaging_unittest.py
diff --git a/mojo/python/tests/messaging_unittest.py b/mojo/python/tests/messaging_unittest.py
index 2d08941ac6b8a60996c2153a3aa70bb8c5c0de91..beb520a5c7ecdfa8ae09da4cacdec8d310700dc6 100644
--- a/mojo/python/tests/messaging_unittest.py
+++ b/mojo/python/tests/messaging_unittest.py
@@ -4,8 +4,9 @@
 
 import unittest
 
+import mojo_unittest
+
 # pylint: disable=F0401
-import mojo.embedder
 from mojo.bindings import messaging
 from mojo import system
 
@@ -19,11 +20,10 @@ class _ForwardingConnectionErrorHandler(messaging.ConnectionErrorHandler):
     self._callback(result)
 
 
-class ConnectorTest(unittest.TestCase):
+class ConnectorTest(mojo_unittest.MojoTestCase):
 
   def setUp(self):
-    mojo.embedder.Init()
-    self.loop = system.RunLoop()
+    super(ConnectorTest, self).setUp()
     self.received_messages = []
     self.received_errors = []
     def _OnMessage(message):
@@ -44,7 +44,7 @@ class ConnectorTest(unittest.TestCase):
   def tearDown(self):
     self.connector = None
     self.handle = None
-    self.loop = None
+    super(ConnectorTest, self).tearDown()
 
   def testConnectorRead(self):
     self.handle.WriteMessage()
@@ -134,11 +134,10 @@ class HeaderTest(unittest.TestCase):
     self.assertEqual(other_header.request_id, 0xdeadbeafdeadbeaf)
 
 
-class RouterTest(unittest.TestCase):
+class RouterTest(mojo_unittest.MojoTestCase):
 
   def setUp(self):
-    mojo.embedder.Init()
-    self.loop = system.RunLoop()
+    super(RouterTest, self).setUp()
     self.received_messages = []
     self.received_errors = []
     def _OnMessage(message):
@@ -158,7 +157,7 @@ class RouterTest(unittest.TestCase):
   def tearDown(self):
     self.router = None
     self.handle = None
-    self.loop = None
+    super(RouterTest, self).tearDown()
 
   def testSimpleMessage(self):
     header_data = messaging.MessageHeader(0, messaging.NO_FLAG).Serialize()