[Predator] Add TouchCrashedFileMetaFeature.

appengine/findit/crash/crash_util.py

Index: appengine/findit/crash/crash_util.py
diff --git a/appengine/findit/crash/crash_util.py b/appengine/findit/crash/crash_util.py
index a17a4e503461d1352041401a2f587e16176fe599..56947a5436ef37a07fea6e37489b955bd51e4354 100644
--- a/appengine/findit/crash/crash_util.py
+++ b/appengine/findit/crash/crash_util.py
@@ -23,6 +23,12 @@ def IsSameFilePath(path_1, path_2):
   Returns:
     Boolean, True if it they are thought to be a same path, False otherwise.
   """
+  if not path_1 and not path_2:
+    return True
+
+  if not path_1 or not path_2:
+    return False
+
   # TODO(katesonia): Think of better way to determine whether 2 paths are the
   # same or not.
   path_parts_1 = path_1.lower().split('/')