[Part 1 of 6] Move MockWebContentsTaskManager into its own file.

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 429 matching lines @@
       'browser/ssl/chrome_ssl_host_state_delegate_test.cc',
       'browser/ssl/ssl_browser_tests.cc',
       'browser/ssl/ssl_client_certificate_selector_test.cc',
       'browser/ssl/ssl_client_certificate_selector_test.h',
       'browser/storage/durable_storage_browsertest.cc',
       'browser/sync_file_system/mock_local_change_processor.cc',
       'browser/sync_file_system/mock_local_change_processor.h',
       'browser/sync_file_system/mock_remote_file_sync_service.cc',
       'browser/sync_file_system/mock_remote_file_sync_service.h',
       'browser/tab_contents/view_source_browsertest.cc',
+      'browser/task_management/mock_web_contents_task_manager.cc',
+      'browser/task_management/mock_web_contents_task_manager.h',
       'browser/task_management/providers/web_contents/background_contents_tag_browsertest.cc',
       'browser/task_management/providers/web_contents/devtools_tag_browsertest.cc',
       'browser/task_management/providers/web_contents/extension_tag_browsertest.cc',
       'browser/task_management/providers/web_contents/subframe_task_browsertest.cc',
       'browser/task_management/providers/web_contents/tab_contents_tag_browsertest.cc',
       'browser/task_manager/task_manager_browsertest.cc',
       'browser/task_manager/task_manager_browsertest_util.cc',
       'browser/task_manager/task_manager_browsertest_util.h',
       'browser/themes/theme_service_browsertest.cc',
       'browser/tracing/chrome_tracing_delegate_browsertest.cc',
@@ skipping 3118 matching lines @@
             'browser',
           ],
           'sources': [
             'tools/service_discovery_sniffer/service_discovery_sniffer.cc',
             'tools/service_discovery_sniffer/service_discovery_sniffer.h',
           ],
         }]
     }],
   ],  # 'conditions'
 }