Add logs for update_engine and image_to_live to test artifacts.

bin/au_test_harness/au_test.py

 # Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Module containing a test suite that is run to test auto updates."""
 
 import os
 import tempfile
 import time
 import unittest
@@ skipping 40 matching lines @@
     if not cls.base_image_path:
       cros_lib.Die('Need path to base image for vm.')
     elif not os.path.exists(cls.base_image_path):
       cros_lib.Die('%s does not exist' % cls.base_image_path)
 
     if not cls.target_image_path:
       cros_lib.Die('Need path to target image to update with.')
     elif not os.path.exists(cls.target_image_path):
       cros_lib.Die('%s does not exist' % cls.target_image_path)
 
-    # Initialize test root.
+    # Initialize test root.  Test root path must be in the chroot.
     if not cls.test_results_root:
       if options.test_results_root:
+        assert 'chroot/tmp' in options.test_results_root, \
+          'Must specify a test results root inside tmp in a chroot.'
         cls.test_results_root = options.test_results_root
       else:
-        cls.test_results_root = tempfile.mkdtemp(prefix='au_test_harness')
+        cls.test_results_root = tempfile.mkdtemp(
+            prefix='au_test_harness',
+            dir=cros_lib.PrependChrootPath('/tmp'))
 
       cros_lib.Info('Using %s as the test results root' % cls.test_results_root)
 
     # Cache away options to instantiate workers later.
     cls.options = options
 
   def AttemptUpdateWithPayloadExpectedFailure(self, payload, expected_msg):
     """Attempt a payload update, expect it to fail with expected log"""
     try:
       self.worker.UpdateUsingPayload(payload)
@@ skipping 197 matching lines @@
     url = 'http://gsdview.appspot.com/chromeos-localmirror/' \
           'autest-images/corrupted_image.gz'
     payload = os.path.join(self.download_folder, 'corrupted.gz')
 
     # Read from the URL and write to the local file
     urllib.urlretrieve(url, payload)
 
     # This update is expected to fail...
     expected_msg = 'zlib inflate() error:-3'
     self.AttemptUpdateWithPayloadExpectedFailure(payload, expected_msg)