Add shell::Tracer object and wire up to --trace-startup on Android

PRESUBMIT_test.py

 #!/usr/bin/env python
 # 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.
 
 import re
 import unittest
 
 import PRESUBMIT
 from PRESUBMIT_test_mocks import MockChange, MockFile
@@ skipping 376 matching lines @@
       'components/nacl/common/DEPS',
       'content/public/browser/render_process_host.h',
       'policy/DEPS',
       'sandbox/DEPS',
       'tools/memory_watcher/DEPS',
       'third_party/lss/linux_syscall_support.h',
     ])
     self.assertEqual(expected, files_to_check);
 
 
-class JSONParsingTest(unittest.TestCase):
-  def testSuccess(self):
-    input_api = MockInputApi()
-    filename = 'valid_json.json'
-    contents = ['// This is a comment.',
-                '{',
-                '  "key1": ["value1", "value2"],',
-                '  "key2": 3  // This is an inline comment.',
-                '}'
-                ]
-    input_api.files = [MockFile(filename, contents)]
-    self.assertEqual(None,
-                     PRESUBMIT._GetJSONParseError(input_api, filename))
-
-  def testFailure(self):
-    input_api = MockInputApi()
-    test_data = [
-      ('invalid_json_1.json',
-       ['{ x }'],
-       'Expecting property name:'),
-      ('invalid_json_2.json',
-       ['// Hello world!',
-        '{ "hello": "world }'],
-       'Unterminated string starting at:'),
-      ('invalid_json_3.json',
-       ['{ "a": "b", "c": "d", }'],
-       'Expecting property name:'),
-      ('invalid_json_4.json',
-       ['{ "a": "b" "c": "d" }'],
-       'Expecting , delimiter:'),
-      ]
-
-    input_api.files = [MockFile(filename, contents)
-                       for (filename, contents, _) in test_data]
-
-    for (filename, _, expected_error) in test_data:
-      actual_error = PRESUBMIT._GetJSONParseError(input_api, filename)
-      self.assertTrue(expected_error in str(actual_error),
-                      "'%s' not found in '%s'" % (expected_error, actual_error))
-
-  def testNoEatComments(self):

[viettrungluu, 2015/04/07 22:05:44]

Maybe keep this test (and rename it)?

[jamesr, 2015/04/07 22:20:07]

At this point it's just testing the JSON parser which is input_api.json and
mocked out in this test. I don't think we really need a unit test of python's
json parser in this file

-    input_api = MockInputApi()
-    file_with_comments = 'file_with_comments.json'
-    contents_with_comments = ['// This is a comment.',
-                              '{',
-                              '  "key1": ["value1", "value2"],',
-                              '  "key2": 3  // This is an inline comment.',
-                              '}'
-                              ]
-    file_without_comments = 'file_without_comments.json'
-    contents_without_comments = ['{',
-                                 '  "key1": ["value1", "value2"],',
-                                 '  "key2": 3',
-                                 '}'
-                                 ]
-    input_api.files = [MockFile(file_with_comments, contents_with_comments),
-                       MockFile(file_without_comments,
-                                contents_without_comments)]
-
-    self.assertEqual('No JSON object could be decoded',
-                     str(PRESUBMIT._GetJSONParseError(input_api,
-                                                      file_with_comments,
-                                                      eat_comments=False)))
-    self.assertEqual(None,
-                     PRESUBMIT._GetJSONParseError(input_api,
-                                                  file_without_comments,
-                                                  eat_comments=False))
-
 if __name__ == '__main__':
   unittest.main()