[Findit] Modify the handler for fracas input message.

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
 
 from google.appengine.ext import ndb
 
 from model.crash.crash_analysis import CrashAnalysis
 
 
 class FracasCrashAnalysis(CrashAnalysis):
   """Represents an analysis of a Chrome crash."""
   # Data of crash per million page loads for each Chrome version.
-  versions_to_cpm = ndb.JsonProperty(indexed=False)
+  versions_to_historical = ndb.JsonProperty(indexed=False)
 
   def Reset(self):
     super(FracasCrashAnalysis, self).Reset()
-    self.versions_to_cpm = None
+    self.versions_to_historical = None
 
   @ndb.ComputedProperty
   def channel(self):
     return self.key.pairs()[0][1].split('/')[0]
 
   @ndb.ComputedProperty
   def platform(self):
     return self.key.pairs()[0][1].split('/')[1]
 
   @staticmethod
   def _CreateKey(channel, platform, signature):
     # Use sha1 hex digest of signature to avoid char conflict with '/'.
     return ndb.Key('FracasCrashAnalysis', '%s/%s/%s' % (
         channel, platform, hashlib.sha1(signature).hexdigest()))
 
   @classmethod
   def Get(cls, channel, platform, signature):
     return cls._CreateKey(channel, platform, signature).get()
 
   @classmethod
   def Create(cls, channel, platform, signature):
     analysis = cls(key=cls._CreateKey(channel, platform, signature))
     analysis.signature = signature
     return analysis