[Predator] Add TouchCrashedDirectory feature.

appengine/findit/crash/crash_data.py

 # Copyright 2017 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 collections import namedtuple
 
 from crash.chromecrash_parser import ChromeCrashParser
 from crash import detect_regression_range
 from crash.stacktrace import Stacktrace
@@ skipping 37 matching lines @@
           'signature': '[ThreadWatcher UI hang] base::RunLoopBase::Run',
           'crash_identifiers': {    # A list of key-value to identify a crash.
             ...
           }
       }
     """
     self._identifiers = crash_data['crash_identifiers']
     self._crashed_version = crash_data['chrome_version']
     self._signature = crash_data['signature']
     self._platform = crash_data['platform']
+    self._stacktrace_str = crash_data['stack_trace'] or ''
 
   @property
   def identifiers(self):
     return self._identifiers
 
   @property
   def crashed_version(self):
     return self._crashed_version
 
   @property
@@ skipping 16 matching lines @@
   def regression_range(self):
     raise NotImplementedError()
 
   @property
   def dependencies(self):
     raise NotImplementedError()
 
   @property
   def dependency_rolls(self):
     raise NotImplementedError()