Re-land first pass BackgroundTracingManager.

content/content_browser.gypi

 # Copyright (c) 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.
 
 {
   'dependencies': [
     '../base/base.gyp:base_static',
     '../crypto/crypto.gyp:crypto',
     '../device/vibration/vibration.gyp:device_vibration',
     '../device/vibration/vibration.gyp:device_vibration_mojo_bindings',
@@ skipping 1417 matching lines @@
       'browser/theme_helper_mac.h',
       'browser/theme_helper_mac.mm',
       'browser/time_zone_monitor.cc',
       'browser/time_zone_monitor.h',
       'browser/time_zone_monitor_android.cc',
       'browser/time_zone_monitor_android.h',
       'browser/time_zone_monitor_chromeos.cc',
       'browser/time_zone_monitor_linux.cc',
       'browser/time_zone_monitor_mac.mm',
       'browser/time_zone_monitor_win.cc',
+      'browser/tracing/background_tracing_endpoint.cc',
+      'browser/tracing/background_tracing_endpoint.h',
+      'browser/tracing/background_tracing_manager.cc',
+      'browser/tracing/background_tracing_manager.h',
+      'browser/tracing/background_tracing_scenario.cc',
+      'browser/tracing/background_tracing_scenario.h',
       'browser/tracing/etw_system_event_consumer_win.cc',
       'browser/tracing/etw_system_event_consumer_win.h',
       'browser/tracing/trace_message_filter.cc',
       'browser/tracing/trace_message_filter.h',
       'browser/tracing/tracing_controller_impl.cc',
       'browser/tracing/tracing_controller_impl.h',
       'browser/tracing/tracing_ui.cc',
       'browser/tracing/tracing_ui.h',
       'browser/transition_request_manager.cc',
       'browser/transition_request_manager.h',
@@ skipping 583 matching lines @@
         'browser/media/media_web_contents_observer.h',
       ],
     }],
     ['OS == "linux" and use_openssl==1', {
       'dependencies': [
         '../third_party/boringssl/boringssl.gyp:boringssl',
       ],
     }],
   ],
 }