Add --trace-rotate-startup-file option and store unsaved trace data on exit.

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',
     '../google_apis/google_apis.gyp:google_apis',
     '../net/net.gyp:net',
@@ skipping 1294 matching lines @@
       '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/theme_helper_mac.mm',
       'browser/theme_helper_mac.h',
+      'browser/tracing/add_new_file_index.cc',
+      'browser/tracing/add_new_file_index.h',
       'browser/tracing/trace_message_filter.cc',
       'browser/tracing/trace_message_filter.h',
       'browser/tracing/etw_system_event_consumer_win.cc',
       'browser/tracing/etw_system_event_consumer_win.h',
       'browser/tracing/tracing_controller_impl.cc',
       'browser/tracing/tracing_controller_impl.h',
       'browser/tracing/tracing_ui.cc',
       'browser/tracing/tracing_ui.h',
       'browser/udev_linux.cc',
       'browser/udev_linux.h',
@@ skipping 431 matching lines @@
         '../build/linux/system.gyp:dbus',
         '../dbus/dbus.gyp:dbus',
       ],
     }, {  # OS != "linux" or use_dbus==0
       'sources!': [
         'browser/geolocation/wifi_data_provider_linux.cc',
       ],
     }],
   ],
 }