[Android] Remove chromium version of devil.

build/android/devil/utils/lazy/weak_constant.py

-# Copyright 2015 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 threading
-
-
-class WeakConstant(object):
-  """A thread-safe, lazily initialized object.
-
-  This does not support modification after initialization. The intended
-  constant nature of the object is not enforced, though, hence the "weak".
-  """
-
-  def __init__(self, initializer):
-    self._initialized = False
-    self._initializer = initializer
-    self._lock = threading.Lock()
-    self._val = None
-
-  def read(self):
-    """Get the object, creating it if necessary."""
-    if self._initialized:
-      return self._val
-    with self._lock:
-      if not self._initialized:
-        self._val = self._initializer()
-        self._initialized = True
-    return self._val