Allow unit tests to force serial execution in the test launcher.

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': {
     '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',
       'browser/extensions/browsertest_util.cc',
@@ skipping 865 matching lines @@
       'test/data/webui/net_internals/timeline_view.js',
       'test/data/webui/net_internals/waterfall_view.js',
       'test/data/webui/net_internals/sdch_view.js',
       'test/data/webui/ntp4.js',
       'test/data/webui/print_preview.js',
       'test/data/webui/sandboxstatus_browsertest.js',
     ],
     'chrome_interactive_ui_test_sources': [
       '../extensions/browser/app_window/app_window_interactive_uitest.cc',
       '../ui/base/clipboard/clipboard_android_unittest.cc',
-      '../ui/base/clipboard/clipboard_unittest.cc',
       'browser/apps/app_browsertest_util.cc',
       'browser/apps/app_browsertest_util.h',
       'browser/apps/app_pointer_lock_interactive_uitest.cc',
       'browser/apps/app_shim/app_shim_interactive_uitest_mac.mm',
       'browser/apps/app_shim/app_shim_quit_interactive_uitest_mac.mm',
       'browser/apps/app_window_interactive_uitest.cc',
       'browser/apps/app_window_intercept_all_keys_uitest.cc',
       'browser/apps/guest_view/web_view_interactive_browsertest.cc',
       'browser/autofill/autofill_interactive_uitest.cc',
       'browser/autofill/autofill_uitest_util.cc',
@@ skipping 2277 matching lines @@
             ['enable_webrtc==1', {
               'dependencies': [
                 '../third_party/libjingle/libjingle.gyp:libjingle_webrtc'
               ]
             }],
           ],
         }]
     }],
   ],  # 'conditions'
 }