[Findit] Add iterator and crash_iterator for delta test

appengine/findit/model/crash/test/chrome_crash_analysis_test.py

Index: appengine/findit/model/crash/test/chrome_crash_analysis_test.py
diff --git a/appengine/findit/model/crash/test/chrome_crash_analysis_test.py b/appengine/findit/model/crash/test/chrome_crash_analysis_test.py
index 7f0878f16199e2d92d5eca1c9e6a19452382cb0d..5bf141030fb7b21091f2219c247d46dbddfc58ab 100644
--- a/appengine/findit/model/crash/test/chrome_crash_analysis_test.py
+++ b/appengine/findit/model/crash/test/chrome_crash_analysis_test.py
@@ -33,3 +33,13 @@ class ChromeCrashAnalysisTest(CrashTestCase):
     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'})