Add an experiment for the default browser infobar on Windows 10

chrome/chrome_tests_unit.gypi

 # Copyright 2012 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_unit_tests_sources': [
       # histograms.xml is analyzed by AboutFlagsHistogramTest, so this
       # dependency is needed to make commit bots run unit_tests on
       # histograms.xml changes.
       '../tools/metrics/histograms/histograms.xml',
@@ skipping 2422 matching lines @@
           ],
         }],
         ['chromeos==0 and OS=="linux"', {
           'sources': [ '<@(chrome_unit_tests_desktop_linux_sources)' ],
         }],
         ['OS!="android" and OS!="ios" and chromeos==0', {
           'sources': [
             'browser/net/disk_cache_dir_policy_handler_unittest.cc',
             'browser/profiles/profile_list_desktop_unittest.cc',
             'browser/profiles/profile_statistics_unittest.cc',
+            'browser/ui/startup/default_browser_infobar_delegate_unittest.cc',
           ],
         }],
         ['chromeos==0 and use_ozone==0 and OS=="linux"', {
           'dependencies': [
             'browser/ui/libgtk2ui/libgtk2ui.gyp:gtk2ui',
             '../build/linux/system.gyp:gio',
           ],
         }],
         ['use_aura==1 or toolkit_views==1', {
           'dependencies': [
@@ skipping 548 matching lines @@
               'dependencies': [
                 '../tools/xdisplaycheck/xdisplaycheck.gyp:xdisplaycheck',
               ],
             }],
           ],
         },
       ],
     }],
   ],  # 'conditions'
 }