Add an end-to-end test for symbolize_trace on macOS.

tracing/bin/run_symbolize_trace_tests

+#!/usr/bin/env python
+# Copyright 2017 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 filecmp
+import os
+import shutil
+import subprocess
+import sys
+import tempfile
+
+_THIS_DIR_PATH = os.path.abspath(os.path.dirname(os.path.realpath(__file__)))
+
+sys.path.insert(0, _THIS_DIR_PATH)
+import symbolize_trace
+
+
+def _DownloadFromCloudStorage(path):
+  BUCKET = 'chrome-partner-telemetry'
+  args = [ 'download_from_google_storage.py', '-s', path + '.sha1', '--bucket', BUCKET ]

[etienneb, 2017/06/20 03:28:09]

split line

[erikchen, 2017/06/23 00:33:45]

Done.

+  subprocess.check_call(args)
+
+
+def GetGzipCrc(path):
+  args = 'gzip -v -l ' + path +  ' | awk \'{print $2}\' | tail -n 1'
+  return subprocess.call(args, shell=True)
+
+def TestMac():
+  trace_presymbolization_path = os.path.join(
+      _THIS_DIR_PATH, 'data', 'mac_trace_presymbolization.json.gz')
+  _DownloadFromCloudStorage(trace_presymbolization_path)
+
+  trace_postsymbolization_path = os.path.join(
+      _THIS_DIR_PATH, 'data', 'mac_trace_postsymbolization.json.gz')
+  _DownloadFromCloudStorage(trace_postsymbolization_path)
+
+  _, temporary_trace = tempfile.mkstemp(suffix='.json.gz')
+  try:
+    shutil.copy(trace_presymbolization_path, temporary_trace)
+    symbolize_trace.main(['--only-symbolize-chrome-symbols',
+                         temporary_trace])
+    success = (GetGzipCrc(temporary_trace)

[etienneb, 2017/06/20 03:28:09]

why comparing CRC?
File comparison should be the same cost.

This way we can avoid the shell commands, and I may be able to port this test to
windows.

[erikchen, 2017/06/23 00:33:45]

gzip files have a timestamp built in, so can't be directly compared.

+               == GetGzipCrc(trace_postsymbolization_path))
+    print 'Success: ' + str(success)
+  finally:
+    os.remove(temporary_trace)
+
+
+if __name__ == '__main__':
+  if sys.platform == 'darwin':
+    TestMac()