[Findit] Add cracas_crash_analysis

appengine/findit/model/crash/fracas_crash_analysis.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 hashlib
-import json
-
 from google.appengine.ext import ndb
 
-from model.crash.crash_analysis import CrashAnalysis
+from model.crash.chrome_crash_analysis import ChromeCrashAnalysis
 
 
-class FracasCrashAnalysis(CrashAnalysis):
-  """Represents an analysis of a Chrome crash."""
-  # Customized properties for Fracas crash.
-  historical_metadata = ndb.JsonProperty(indexed=False)
-  channel = ndb.StringProperty(indexed=False)
-
-  def Reset(self):
-    super(FracasCrashAnalysis, self).Reset()
-    self.historical_metadata = None
-    self.channel = None
-
-  @staticmethod
-  def _CreateKey(crash_identifiers):
-    return ndb.Key('FracasCrashAnalysis', hashlib.sha1(
-        json.dumps(crash_identifiers, sort_keys=True)).hexdigest())
-
-  @classmethod
-  def Get(cls, crash_identifiers):
-    return cls._CreateKey(crash_identifiers).get()
-
-  @classmethod
-  def Create(cls, crash_identifiers):
-    analysis = cls(key=cls._CreateKey(crash_identifiers))
-    return analysis
+class FracasCrashAnalysis(ChromeCrashAnalysis):
+  """Represents an analysis of a Chrome crash on Fracas."""
+  pass