Add logdog_helper script.

build/android/pylib/utils/decorators.py

Index: build/android/pylib/utils/decorators.py
diff --git a/build/android/pylib/utils/decorators.py b/build/android/pylib/utils/decorators.py
new file mode 100644
index 0000000000000000000000000000000000000000..8eec1d1e58e6da46517e7e64c05f917609ceac96
--- /dev/null
+++ b/build/android/pylib/utils/decorators.py
@@ -0,0 +1,37 @@
+# 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 functools
+import logging
+
+
+def Memoize(f):
+  """Decorator to cache return values of function."""
+  memoize_dict = {}
+  @functools.wraps(f)
+  def wrapper(*args, **kwargs):
+    key = repr((args, kwargs))
+    if key not in memoize_dict:
+      memoize_dict[key] = f(*args, **kwargs)
+    return memoize_dict[key]
+  return wrapper
+
+
+def NoRaiseException(default_return_value=None, exception_message=''):
+  """Returns decorator that catches and logs uncaught Exceptions.
+
+  Args:
+    default_return_value: Value to return in the case of uncaught Exception.
+    exception_message: Message for uncaught exceptions.
+  """
+  def decorator(f):
+    @functools.wraps(f)
+    def wrapper(*args, **kwargs):
+      try:
+        return f(*args, **kwargs)
+      except Exception:  # pylint: disable=broad-except
+        logging.exception(exception_message)
+        return default_return_value
+    return wrapper
+  return decorator