Added unit test for stack traces in telemetry crashes.

tools/perf/core/stacktrace_unittest.py

+# Copyright 2015 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.
+
+from telemetry.core import exceptions
+from telemetry import decorators
+from telemetry.testing import tab_test_case
+
+class TabStackTraceTest(tab_test_case.TabTestCase):
+
+  # For now just work on a single platform (mac).
+  @decorators.Enabled('mac')
+  def testStackTrace(self):
+    try:
+      self._tab.Navigate('chrome://crash', timeout=5)
+    except exceptions.DevtoolsTargetCrashException as e:
+      self.assertIn('Thread 0 (crashed)', '\n'.join(e.stack_trace))
+
+  # Currently stack traces do not work on windows: http://crbug.com/476110
+  # Currently symbols do not work on swarming: http://crbug.com/563716
+  # Linux stack traces depends on fission support: http://crbug.com/405623
+  @decorators.Disabled('all')
+  def testCrashSymbols(self):
+    try:
+      self._tab.Navigate('chrome://crash', timeout=5)
+    except exceptions.DevtoolsTargetCrashException as e:
+      self.assertIn('CrashIntentionally', '\n'.join(e.stack_trace))