Telemetry support for extensions.

tools/telemetry/telemetry/extension_dict.py

+# Copyright (c) 2012 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.
+
+from telemetry import extension_to_load
+
+class ExtensionDict(object):
+  """Dictionary of ExtensionPage instances, with extension_id as key"""
+
+  def __init__(self, extension_dict_backend):
+    self._extension_dict_backend = extension_dict_backend
+
+  def __getitem__(self, load_extension):
+    """Given an ExtensionToLoad instance, returns the corresponding
+    ExtensionPage instance."""
+    if not isinstance(load_extension, extension_to_load.ExtensionToLoad):
+      raise Exception("Input param must be of type ExtensionToLoad")
+    return self._extension_dict_backend.__getitem__(
+        load_extension.extension_id())
+
+  def __contains__(self, load_extension):
+    """Checks if this ExtensionToLoad instance has been loaded"""
+    if not isinstance(load_extension, extension_to_load.ExtensionToLoad):
+      raise Exception("Input param must be of type ExtensionToLoad")
+    return self._extension_dict_backend.__contains__(
+        load_extension.extension_id())