[Predator] Switch from scorer-based classifier to loglinear classifier.

appengine/findit/crash/project_classifier.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 logging
 
 from crash.occurrence import RankByOccurrence
 from crash.project import Project
 from crash.type_enums import LanguageType
 from model.crash.crash_config import CrashConfig
@@ skipping 29 matching lines @@
 
     Args:
       suspects (list of Suspect): culprit suspects.
 
     Returns:
       The name of the most-suspected project; or the empty string on failure.
     """
     rank_function = None
     if crash_stack.language_type == LanguageType.JAVA:
       def RankFunctionForJava(occurrence):
-        # TODO(wrengr): why are we weighting by the length, instead of
-        # the negative length as we do in the DefaultOccurrenceRanging?
-        weight = len(occurrence)
-        project_name = occurrence.name
-        if 'chromium' in project_name:
+        if 'chromium' in occurrence.name:
           index = 0
         else:
-          index = self.non_chromium_project_rank_priority[project_name]
-        return (weight, index)
+          index = self.non_chromium_project_rank_priority[occurrence.name]
+        return -len(occurrence), index
 
       rank_function = RankFunctionForJava
 
     def GetProjectFromStackFrame(frame):
       """Determine which project is responsible for this frame."""
       for project in self.projects:
         if project.MatchesStackFrame(frame):
           return project.GetName(frame.dep_path)
 
       return None
@@ skipping 26 matching lines @@
 
     Args:
       suspects (list of Suspect): culprit suspects.
 
     Returns:
       The name of the most-suspected project; or the empty string on failure.
     """
     projects = map(self.ClassifySuspect, suspects)
     return ProjectClassifier._GetTopProject(projects,
                                             rank_function=lambda x:-len(x))