Refactor the python system_impl module.

mojo/PRESUBMIT.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.
 
 """Presubmit script for mojo
 
 See http://dev.chromium.org/developers/how-tos/depottools/presubmit-scripts
 for more details about the presubmit API built into depot_tools.
 """
 
 import os.path
 import re
 
 _SDK_WHITELISTED_EXTERNAL_PATHS = [
   "//testing/gtest",
   "//third_party/cython",
   "//third_party/khronos",
 ]
 
 _PACKAGE_PATH_PREFIXES = {"SDK": "mojo/public/",
                           "EDK": "mojo/edk/"}
 
-_PACKAGE_SOURCE_SET_TYPES = {"SDK": "mojo_sdk_source_set",
-                             "EDK": "mojo_edk_source_set"}
+_PACKAGE_SOURCE_SET_TYPES = {"SDK": ["mojo_sdk_source_set",
+                                     "python_binary_source_set"],
+                             "EDK": ["mojo_edk_source_set"]}
 
 _ILLEGAL_EXTERNAL_PATH_WARNING_MESSAGE = \
     "Found disallowed external paths within SDK buildfiles."
 
 _ILLEGAL_EDK_ABSOLUTE_PATH_WARNING_MESSAGE = \
     "Found references to the EDK via absolute paths within EDK buildfiles.",
 
 _ILLEGAL_SDK_ABSOLUTE_PATH_WARNING_MESSAGE_TEMPLATE = \
     "Found references to the SDK via absolute paths within %s buildfiles."
 
@@ skipping 119 matching lines @@
   assert package in _PACKAGE_SOURCE_SET_TYPES
   required_source_set_type = _PACKAGE_SOURCE_SET_TYPES[package]
 
   problems = []
   for f in _AffectedBuildFilesWithinPackage(input_api, package):
     for line_num, line in f.ChangedContents():
       m = re.search(r"[a-z_]*source_set\(", line)
       if not m:
         continue
       source_set_type = m.group(0)[:-1]
-      if source_set_type == required_source_set_type:
+      if source_set_type in required_source_set_type:
         continue
       problems.append(_IncorrectSourceSetTypeWarningItem(f.LocalPath(),
                                                          line_num))
 
   if not problems:
     return []
   return [output_api.PresubmitError(
       _INCORRECT_SOURCE_SET_TYPE_WARNING_MESSAGES[package],
       items=problems)]
 
@@ skipping 60 matching lines @@
 def CheckChangeOnUpload(input_api, output_api):
   results = []
   results.extend(_CommonChecks(input_api, output_api))
   results.extend(_CheckChangePylintsClean(input_api, output_api))
   return results
 
 def CheckChangeOnCommit(input_api, output_api):
   results = []
   results.extend(_CommonChecks(input_api, output_api))
   return results