Upgrade loading_model to use the new request_track and loading_trace.

tools/android/loading/request_track_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 json
 import unittest
 
 from request_track import (Request, RequestTrack, TimingFromDict)
 
 
@@ skipping 250 matching lines @@
     self._ValidSequence(self.request_track)
     json_dict = self.request_track.ToJsonDict()
     _ = json.dumps(json_dict)  # Should not raise an exception.
 
   def testCanDeserialize(self):
     self._ValidSequence(self.request_track)
     json_dict = self.request_track.ToJsonDict()
     request_track = RequestTrack.FromJsonDict(json_dict)
     self.assertEquals(self.request_track, request_track)
 
+  def testMaxAge(self):
+    rq = Request()
+    self.assertEqual(-1, rq.MaxAge())
+    rq.response_headers = {}
+    self.assertEqual(-1, rq.MaxAge())
+    rq.response_headers[
+        'Cache-Control'] = 'private,s-maxage=0,max-age=0,must-revalidate'
+    self.assertEqual(0, rq.MaxAge())
+    rq.response_headers[
+        'Cache-Control'] = 'private,s-maxage=0,no-store,max-age=100'
+    self.assertEqual(-1, rq.MaxAge())
+    rq.response_headers[
+        'Cache-Control'] = 'private,s-maxage=0'
+    self.assertEqual(-1, rq.MaxAge())
+
   @classmethod
   def _ValidSequence(cls, request_track):
     request_track.Handle(
         'Network.requestWillBeSent', cls._REQUEST_WILL_BE_SENT)
     request_track.Handle('Network.responseReceived', cls._RESPONSE_RECEIVED)
     request_track.Handle('Network.dataReceived', cls._DATA_RECEIVED_1)
     request_track.Handle('Network.dataReceived', cls._DATA_RECEIVED_2)
     request_track.Handle('Network.loadingFinished', cls._LOADING_FINISHED)
 
 if __name__ == '__main__':
   unittest.main()