[Findit] Add iterator and crash_iterator for delta test

appengine/findit/model/crash/test/chrome_crash_analysis_test.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.
 
 from datetime import datetime
 
 from crash.test.crash_testcase import CrashTestCase
 from model import analysis_status
 from model import result_status
 from model.crash.chrome_crash_analysis import ChromeCrashAnalysis
@@ skipping 15 matching lines @@
     self.assertIsNone(analysis.signature)
     self.assertIsNone(analysis.channel)
     self.assertIsNone(analysis.platform)
 
   def testChromeCrashAnalysisReset(self):
     analysis = ChromeCrashAnalysis()
     analysis.historical_metadata = {}
     analysis.Reset()
     self.assertIsNone(analysis.channel)
     self.assertIsNone(analysis.historical_metadata)
+
+  def testChromeCrashAnalysisCustomizedProperty(self):
+    analysis = ChromeCrashAnalysis()
+    analysis.historical_metadata = {'chrome_version': '50.0.1200.0',
+                                    'cpm': 0.5}
+    analysis.channel = 'canary'
+    self.assertEqual(analysis.customized_data,
+                     {'historical_metadata': {'chrome_version': '50.0.1200.0',
+                                              'cpm': 0.5},
+                      'channel': 'canary'})