[Findit] Add three sub-pipelines to analyze build failure.

appengine/findit/waterfall/extractor.py

-# Copyright (c) 2014 The Chromium Authors. All rights reserved.
+# Copyright 2014 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 waterfall import extractor_util
 
 
 class Extractor(object):
   """An interface to extract failure signal from a failed step or test."""
 
   def ExtractFiles(self, message_line, failure_signal):
     """Extract files from given message line into ``failure_signal``."""
     match = extractor_util.PYTHON_STACK_TRACE_PATTERN.match(message_line)
     if match:
       trace_line = match.groupdict()
-      failure_signal.AddFile(trace_line['file'], trace_line['line'])
+      failure_signal.AddFile(
+          extractor_util.NormalizeFilePath(trace_line['file']),
+          trace_line['line'])
     else:
       for match in extractor_util.FILE_PATH_LINE_PATTERN.finditer(message_line):
         file_path, line_number = match.groups()
         failure_signal.AddFile(extractor_util.NormalizeFilePath(file_path),
                                line_number)
 
 
   # pylint disable=W0613, R0201
   def Extract(self, failure_log, test_name, step_name, bot_name, master_name):
     """Analyze ``failure_log``, extract and return a FailureSignal."""
     raise NotImplementedError()