There is a cyclic import in dmprof

tools/deep_memory_profiler/lib/deep_dump.py

 # 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.
 
 import copy
 import datetime
 import logging
 import os
 import re
 import time
@@ skipping 133 matching lines @@
     Args:
         path: A file path string to load.
         log_header: A preceding string for log messages.
 
     Returns:
         A loaded Dump object.
 
     Raises:
         ParsingException for invalid heap profile dumps.
     """
-    dump = Dump(path, os.stat(path).st_mtime)
+    dump = DeepDump(path, os.stat(path).st_mtime)
     with open(path, 'r') as f:
       dump.load_file(f, log_header)
     return dump
 
   def load_file(self, f, log_header):
     self._lines = [line for line in f
                    if line and not line.startswith('#')]
 
     try:
       self._version, ln = self._parse_version()
@@ skipping 291 matching lines @@
   Returns:
       A pair of an integer indicating a line number after skipped, and a
       boolean value which is True if found a line which skipping_condition
       is False for.
   """
   while skipping_condition(index):
     index += 1
     if index >= max_index:
       return index, False
   return index, True