[Closure Externs] Add more APIs to the presubmit warning list

Add a bunch of private APIs to the list that will get presubmit checks. Also
normalize the paths and check that each exists.

BUG=469920

Review URL: https://codereview.chromium.org/1761663002

Cr-Commit-Position: refs/heads/master@{#380488}

chrome/common/extensions/api/PRESUBMIT.py

+# Copyright 2016 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.
+
+"""Chromium presubmit script for src/extensions/common.
+
+See http://dev.chromium.org/developers/how-tos/depottools/presubmit-scripts
+for more details on the presubmit API built into depot_tools.
+"""
+
+import sys
+
+
+def _CheckExterns(input_api, output_api):
+  original_sys_path = sys.path
+
+  join = input_api.os_path.join
+  api_root = input_api.PresubmitLocalPath()
+  src_root = join(api_root, '..', '..', '..', '..')
+  try:
+    sys.path.append(join(src_root, 'extensions', 'common', 'api'))
+    from externs_checker import ExternsChecker
+  finally:
+    sys.path = original_sys_path
+
+  externs_root = join(src_root, 'third_party', 'closure_compiler', 'externs')
+
+  api_pair_names = {
+    'autofill_private.idl': 'autofill_private.js',
+    'developer_private.idl': 'developer_private.js',
+    'bookmark_manager_private.json': 'bookmark_manager_private.js',
+    'command_line_private.json': 'command_line_private.js',
+    'file_manager_private.idl': 'file_manager_private.js',
+    'language_settings_private.idl': 'language_settings_private.js',
+    'metrics_private.json': 'metrics_private.js',
+    'passwords_private.idl': 'passwords_private.js',
+    'system_private.json': 'system_private.js',
+    'users_private.idl': 'users_private.js',
+    # TODO(rdevlin.cronin): Add more!
+  }
+  normpath = input_api.os_path.normpath
+  api_pairs = {
+      normpath(join(api_root, k)):
+          normpath(join(externs_root, v)) for k, v in api_pair_names.items()
+  }
+
+  return ExternsChecker(input_api, output_api, api_pairs).RunChecks()
+
+
+def CheckChangeOnUpload(input_api, output_api):
+  return _CheckExterns(input_api, output_api)

extensions/common/api/externs_checker.py

@@ -12,6 +12,10 @@ class ExternsChecker(object):
     self._output_api = output_api
     self._api_pairs = api_pairs
 
+    for path in api_pairs.keys() + api_pairs.values():
+      if not input_api.os_path.exists(path):
+        raise OSError('Path Not Found: %s' % path)
+
   def RunChecks(self):
     bad_files = []
     affected = [f.AbsoluteLocalPath() for f in self._input_api.AffectedFiles()]

extensions/common/api/externs_checker_test.py

@@ -18,8 +18,9 @@ from PRESUBMIT_test_mocks import MockInputApi, MockOutputApi, MockFile
 class ExternsCheckerTest(unittest.TestCase):
   API_PAIRS = {'a': '1', 'b': '2', 'c': '3'}
 
-  def _runChecks(self, files):
+  def _runChecks(self, files, exists=lambda f: True):
     input_api = MockInputApi()
+    input_api.os_path.exists = exists
     input_api.files = [MockFile(f, '') for f in files]
     output_api = MockOutputApi()
     checker = ExternsChecker(input_api, output_api, self.API_PAIRS)
@@ -58,6 +59,12 @@ class ExternsCheckerTest(unittest.TestCase):
     self.assertEquals(1, len(results[0].items))
     self.assertEquals('c', results[0].items[0])
 
+  def testApiFileDoesNotExist(self):
+    exists = lambda f: f in ['a', 'b', 'c', '1', '2']
+    with self.assertRaises(OSError) as e:
+      self._runChecks(['a'], exists)
+    self.assertEqual('Path Not Found: 3', str(e.exception))
+
 
 if __name__ == '__main__':
   unittest.main()