--- a/testing/marionette/harness/marionette_harness/tests/unit/test_crash.py
+++ b/testing/marionette/harness/marionette_harness/tests/unit/test_crash.py
@@ -1,13 +1,14 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 import glob
+import os
 import shutil
 
 from marionette_driver import Wait
 from marionette_driver.errors import (
     MarionetteException,
     NoSuchWindowException,
     TimeoutException
 )
@@ -37,17 +38,18 @@ class MockMozCrash(object):
             # minidump_files = glob.glob('{}/*.dmp'.format(dump_directory))
             try:
                 minidump_files = Wait(None, timeout=5).until(
                     lambda _: glob.glob('{}/*.dmp'.format(dump_directory))
                 )
             except TimeoutException:
                 minidump_files = []
 
-            shutil.rmtree(dump_directory)
+            if os.path.isdir(dump_directory):
+                shutil.rmtree(dump_directory)
 
             return len(minidump_files)
         else:
             return len(minidump_files) == 0
 
     def log_crashes(self, logger, dump_directory, *args, **kwargs):
         return self.check_for_crashes(dump_directory, *args, **kwargs)
 
@@ -100,45 +102,39 @@ class BaseCrashTestCase(MarionetteTestCa
             """, sandbox=sandbox)
         finally:
             self.marionette.client.socket_timeout = socket_timeout
 
 
 class TestCrash(BaseCrashTestCase):
 
     def test_crash_chrome_process(self):
-        with self.assertRaises(IOError):
-            self.crash(chrome=True)
-            Wait(self.marionette, timeout=self.socket_timeout,
-                 ignored_exceptions=NoSuchWindowException).until(
-                lambda _: self.marionette.get_url(),
-                message="Expected IOError exception for content crash not raised."
-            )
+        self.assertRaisesRegexp(IOError, "Process crashed",
+                                self.crash, chrome=True)
 
         # A crash results in a non zero exit code
         self.assertNotIn(self.marionette.instance.runner.returncode, (None, 0))
 
         self.assertEqual(self.marionette.crashed, 1)
         self.assertIsNone(self.marionette.session)
         self.assertRaisesRegexp(MarionetteException, 'Please start a session',
                                 self.marionette.get_url)
 
         self.marionette.start_session()
         self.assertNotEqual(self.marionette.process_id, self.pid)
 
         self.marionette.get_url()
 
     @run_if_e10s("Content crashes only exist in e10s mode")
     def test_crash_content_process(self):
-        # With MOZ_CRASHREPORTER_SHUTDOWN each window of the browser will be
-        # closed in case of a content crash. So the "unload" handler fires for
-        # the current window, which causes the command to return early.
-        # To check for an IOError, further commands have to be executed until
-        # Firefox has been shutdown.
-        with self.assertRaises(IOError):
+        # For a content process crash and MOZ_CRASHREPORTER_SHUTDOWN set the top
+        # browsing context will be gone first. As such the raised NoSuchWindowException
+        # has to be ignored. To check for the IOError, further commands have to
+        # be executed until the process is gone.
+        with self.assertRaisesRegexp(IOError, "Content process crashed"):
             self.crash(chrome=False)
             Wait(self.marionette, timeout=self.socket_timeout,
                  ignored_exceptions=NoSuchWindowException).until(
                 lambda _: self.marionette.get_url(),
                 message="Expected IOError exception for content crash not raised."
             )
 
         # In the case of a content crash Firefox will be closed and its
@@ -159,46 +155,36 @@ class TestCrash(BaseCrashTestCase):
         self.crash(chrome=True)
 
 
 class TestCrashInSetUp(BaseCrashTestCase):
 
     def setUp(self):
         super(TestCrashInSetUp, self).setUp()
 
-        with self.assertRaises(IOError):
-            self.crash(chrome=True)
-            Wait(self.marionette, timeout=self.socket_timeout,
-                 ignored_exceptions=NoSuchWindowException).until(
-                lambda _: self.marionette.get_url(),
-                message="Expected IOError exception for content crash not raised."
-            )
+        self.assertRaisesRegexp(IOError, "Process crashed",
+                                self.crash, chrome=True)
 
         # A crash results in a non zero exit code
         self.assertNotIn(self.marionette.instance.runner.returncode, (None, 0))
 
         self.assertEqual(self.marionette.crashed, 1)
         self.assertIsNone(self.marionette.session)
 
     def test_crash_in_setup(self):
         self.marionette.start_session()
         self.assertNotEqual(self.marionette.process_id, self.pid)
 
 
 class TestCrashInTearDown(BaseCrashTestCase):
 
     def tearDown(self):
         try:
-            with self.assertRaises(IOError):
-                self.crash(chrome=True)
-                Wait(self.marionette, timeout=self.socket_timeout,
-                     ignored_exceptions=NoSuchWindowException).until(
-                    lambda _: self.marionette.get_url(),
-                    message="Expected IOError exception for content crash not raised."
-                )
+            self.assertRaisesRegexp(IOError, "Process crashed",
+                                    self.crash, chrome=True)
 
             # A crash results in a non zero exit code
             self.assertNotIn(self.marionette.instance.runner.returncode, (None, 0))
 
             self.assertEqual(self.marionette.crashed, 1)
             self.assertIsNone(self.marionette.session)
 
         finally: