Use Chromium's mirror of github for gtest-parallel.

- Move gtest-parallel-wrapper.py to tools-webrtc.
- Update mb.py and mb_unittest.py

BUG=webrtc:7391
NOTRY=True
R=kjellander@webrtc.org

Review-Url: https://codereview.webrtc.org/2785653002
Cr-Commit-Position: refs/heads/master@{#17453}
diff --git a/tools-webrtc/gtest-parallel-wrapper.py b/tools-webrtc/gtest-parallel-wrapper.py
new file mode 100755
index 0000000..c9718e2
--- /dev/null
+++ b/tools-webrtc/gtest-parallel-wrapper.py
@@ -0,0 +1,107 @@
+#!/usr/bin/env python
+
+# Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+#
+# Use of this source code is governed by a BSD-style license
+# that can be found in the LICENSE file in the root of the source
+# tree. An additional intellectual property rights grant can be found
+# in the file PATENTS.  All contributing project authors may
+# be found in the AUTHORS file in the root of the source tree.
+
+"""
+This script acts as an interface between the Chromium infrastructure and
+gtest-parallel, renaming options and translating environment variables into
+flags. Developers should execute gtest-parallel directly.
+
+In particular, this translates the GTEST_SHARD_INDEX and GTEST_TOTAL_SHARDS
+environment variables to the --shard_index and --shard_count flags, and renames
+the --isolated-script-test-output flag to --dump_json_test_results.
+
+Note that the flags unprocessed by this script will passed as arguments to the
+test executable, i.e.
+
+  gtest-parallel-wrapper.py some_test \
+      --isolated-script-test-output=some_dir \
+      --unprocessed_arg_1
+      -- \
+      --unprocessed_arg_2
+
+will be converted into
+
+  python gtest-parallel some_test \
+      --shard_count 1 \
+      --shard_index 0 \
+      --dump_json_test_results some_dir \
+      -- \
+      --unprocessed_arg_1
+      --unprocessed_arg_2
+"""
+
+import argparse
+import os
+import subprocess
+import sys
+
+# GTEST_SHARD_INDEX and GTEST_TOTAL_SHARDS must be removed from the environment
+# otherwise it will be picked up by the binary, causing a bug where only tests
+# in the firsh shard are executed.
+test_env = os.environ.copy()
+gtest_shard_index = test_env.pop('GTEST_SHARD_INDEX', '0')
+gtest_total_shards = test_env.pop('GTEST_TOTAL_SHARDS', '1')
+
+webrtc_root = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+gtest_parallel_path = os.path.join(webrtc_root, 'third_party', 'gtest-parallel',
+                                   'gtest-parallel')
+
+# Ignore '--'. Options unprocessed by this script will be passed to the test as
+# arguments.
+if '--' in sys.argv:
+  del sys.argv[sys.argv.index('--')]
+
+parser = argparse.ArgumentParser()
+parser.add_argument('--isolated-script-test-output', type=str, default=None)
+parser.add_argument('--output_dir', type=str, default=None)
+parser.add_argument('--timeout', type=int, default=None)
+
+options, unprocessed = parser.parse_known_args()
+test_executable = unprocessed[0]
+test_arguments = unprocessed[1:]
+
+gtest_args = [
+    test_executable,
+    '--shard_count',
+    gtest_total_shards,
+    '--shard_index',
+    gtest_shard_index,
+]
+
+# --isolated-script-test-output is used to upload results to the flakiness
+# dashboard. This translation is made because gtest-parallel expects the flag to
+# be called --dump_json_test_results instead.
+if options.isolated_script_test_output:
+  gtest_args += [
+      '--dump_json_test_results',
+      options.isolated_script_test_output,
+  ]
+
+if options.output_dir:
+  gtest_args += [
+      '--output_dir',
+      options.output_dir,
+  ]
+
+if options.timeout:
+  gtest_args += [
+      '--timeout',
+      str(options.timeout),
+  ]
+
+command = [
+    sys.executable,
+    gtest_parallel_path,
+] + gtest_args + ['--'] + test_arguments
+
+print 'gtest-parallel-wrapper: Executing command %s' % ' '.join(command)
+sys.stdout.flush()
+
+sys.exit(subprocess.call(command, env=test_env, cwd=os.getcwd()))