[Telemetry] Migrate browser_test_runner to use typ as the test runner

telemetry/telemetry/testing/browser_test_context.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.
+
+import copy
+import sets
+
+
+_global_test_context = None
+
+
+def GetCopy():
+  return copy.deepcopy(_global_test_context)
+
+
+class TypTestContext(object):
+  """ The TestContext that is used for passing data from the main test process
+  to typ's subprocesses. Those includes:
+     _ finder_options: the commandline options object. This is an instance of
+        telemetry.internal.browser.browser_options.BrowserFinderOptions.
+     _ test_class_name: the name of the test class to be run.
+     _ test_cases_ids_to_run: the ids of the test cases to be run.

[Ken Russell (switch to Gerrit), 2016/12/21 00:12:59]

Grammar: here and throughout: test_cases_ids -> test_case_ids

Could you document what these are? i.e., provide some example?

[nednguyen, 2016/12/21 20:29:04]

Done.

+
+  This object is designed to be pickle-able so that it can be easily pass from
+  the main process to test subprocesses. It also supports immutable mode to
+  ensure its data won't be changed by the subprocesses.
+  """
+  def __init__(self):
+    self._finder_options = None
+    self._test_class_name = None
+    self._test_cases_ids_to_run = set()
+    self._frozen = False
+
+  def Freeze(self):
+    """ Makes the |self| object immutable.
+
+    Calling setter on |self|'s property will throw exception.
+    """
+    assert self._finder_options
+    assert self._test_class_name
+    self._frozen = True
+    self._test_cases_ids_to_run = sets.ImmutableSet(self._test_cases_ids_to_run)
+
+  @property
+  def finder_options(self):
+    return self._finder_options
+
+  @property
+  def test_class_name(self):
+    return self._test_class_name
+
+  @property
+  def test_cases_ids_to_run(self):
+    return self._test_cases_ids_to_run
+
+  @finder_options.setter
+  def finder_options(self, value):
+    assert not self._frozen
+    self._finder_options = value
+
+  @test_class_name.setter
+  def test_class_name(self, value):
+    assert not self._test_class_name
+    self._test_class_name = value