Fixes for how extension ids are calculated, especially for component extensions.

tools/telemetry/telemetry/core/extension_to_load.py

 # Copyright (c) 2013 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 os
 
 from telemetry.core.chrome import crx_id
 
 class ExtensionPathNonExistentException(Exception):
   pass
 
+class MissingPublicKeyException(Exception):
+  pass
+
 class ExtensionToLoad(object):
   def __init__(self, path, is_component=False):
     if not os.path.isdir(path):
       raise ExtensionPathNonExistentException(
           'Extension path not a directory %s' % path)
     self._path = path
     self._local_path = path
     self._is_component = is_component
+    if is_component and not crx_id.HasPublicKey(path):
+      raise MissingPublicKeyException(
+         'Component extension %s must have a public key' % path)
 
   @property
   def extension_id(self):
     """Unique extension id of this extension."""
-    return crx_id.GetCRXAppID(os.path.abspath(self._local_path),
-                              from_test_path=True)
+    if crx_id.HasPublicKey(self._path):
+      # Calculate extension id from the public key.
+      return crx_id.GetCRXAppID(os.path.abspath(self._path))
+    else:
+      # Calculate extension id based on the path on the device.
+      return crx_id.GetCRXAppID(os.path.abspath(self._local_path),
+                                from_file_path=True)
 
   @property
   def path(self):
     """Path to extension source directory."""
     return self._path
 
   @property
   def local_path(self):
     """Path to extension destination directory, for remote instances of
     chrome"""
     return self._local_path
 
   @local_path.setter
   def local_path(self, local_path):
     self._local_path = local_path
 
   @property
   def is_component(self):
     """Whether this extension should be loaded as a component extension."""
     return self._is_component