[Part 2 of 6] Task manager browsertest utils are not actually used in any uitests.

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 1041 matching lines @@
       'browser/extensions/extension_test_notification_observer.cc',
       'browser/extensions/updater/extension_cache_fake.cc',
       'browser/extensions/updater/extension_cache_fake.h',
       'browser/extensions/window_open_interactive_apitest.cc',
       'browser/mouseleave_browsertest.cc',
       'browser/password_manager/password_generation_interactive_uitest.cc',
       'browser/password_manager/password_manager_interactive_uitest.cc',
       'browser/renderer_context_menu/render_view_context_menu_browsertest_util.cc',
       'browser/renderer_context_menu/render_view_context_menu_browsertest_util.h',
       'browser/site_per_process_interactive_browsertest.cc',
-      'browser/task_manager/task_manager_browsertest_util.cc',
       'browser/ui/autofill/autofill_popup_controller_interactive_uitest.cc',
       'browser/ui/browser_focus_uitest.cc',
       'browser/ui/cocoa/apps/app_shim_menu_controller_mac_interactive_uitest.mm',
       'browser/ui/cocoa/apps/quit_with_apps_controller_mac_interactive_uitest.mm',
       'browser/ui/cocoa/panels/panel_cocoa_browsertest.mm',
       'browser/ui/exclusive_access/flash_fullscreen_interactive_browsertest.cc',
       'browser/ui/exclusive_access/fullscreen_controller_interactive_browsertest.cc',
       'browser/ui/exclusive_access/fullscreen_controller_state_interactive_browsertest.cc',
       'browser/ui/find_bar/find_bar_host_interactive_uitest.cc',
       'browser/ui/omnibox/omnibox_view_browsertest.cc',
@@ skipping 2507 matching lines @@
             'browser',
           ],
           'sources': [
             'tools/service_discovery_sniffer/service_discovery_sniffer.cc',
             'tools/service_discovery_sniffer/service_discovery_sniffer.h',
           ],
         }]
     }],
   ],  # 'conditions'
 }