Reset user data directory and disk cache directory after downgrade.

chrome/chrome_tests.gypi

 # Copyright 2013 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.
 {
   'variables': {
     'build_angle_deqp_tests%': 0,
     'chrome_browser_extensions_test_support_sources': [
       # A list of sources which is shared between different browser tests.
       'browser/apps/app_browsertest_util.cc',
       'browser/apps/app_browsertest_util.h',
@@ skipping 2458 matching lines @@
             'browser/media/webrtc_disable_encryption_flag_browsertest.cc',
             'browser/media/webrtc_getmediadevices_browsertest.cc',
             'browser/media/webrtc_perf_browsertest.cc',
             'browser/media/webrtc_simulcast_browsertest.cc',
             'browser/media/webrtc_video_quality_browsertest.cc',
             'browser/media/webrtc_webcam_browsertest.cc',
          ],
         }],
         ['OS=="win"', {
           'sources': [
+            'browser/downgrade/user_data_downgrade_browsertest.cc',
             '<(SHARED_INTERMEDIATE_DIR)/chrome_version/other_version.rc',
             '<(SHARED_INTERMEDIATE_DIR)/ui/resources/ui_unscaled_resources.rc',
           ],
           'include_dirs': [
             '<(DEPTH)/third_party/wtl/include',
           ],
           'dependencies': [
             'chrome_version_resources',
           ],
         }, { # else: OS != "win"
@@ skipping 1089 matching lines @@
             'browser',
           ],
           'sources': [
             'tools/service_discovery_sniffer/service_discovery_sniffer.cc',
             'tools/service_discovery_sniffer/service_discovery_sniffer.h',
           ],
         }]
     }],
   ],  # 'conditions'
 }