Add a Content API around TracingController.

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': [
     'browser/debugger/devtools_resources.gyp:devtools_resources',
     '../base/base.gyp:base_static',
     '../crypto/crypto.gyp:crypto',
     '../net/net.gyp:http_server',
@@ skipping 111 matching lines @@
     'public/browser/sensors.h',
     'public/browser/sensors_listener.h',
     'public/browser/sensors_provider.h',
     'public/browser/session_storage_namespace.h',
     'public/browser/site_instance.h',
     'public/browser/speech_recognition_manager.h',
     'public/browser/speech_recognition_manager_delegate.h',
     'public/browser/speech_recognition_preferences.h',
     'public/browser/speech_recognizer.h',
     'public/browser/speech_recognizer_delegate.h',
+    'public/browser/trace_controller.h',
+    'public/browser/trace_subscriber.h',
     'public/browser/user_metrics.h',
     'public/browser/utility_process_host.h',
     'public/browser/web_contents.h',
     'public/browser/web_contents_delegate.cc',
     'public/browser/web_contents_delegate.h',
     'public/browser/web_contents_observer.cc',
     'public/browser/web_contents_observer.h',
     'public/browser/web_contents_view.h',
     'public/browser/web_contents_view_gtk_delegate.h',
     'public/browser/web_contents_view_mac_delegate.h',
@@ skipping 519 matching lines @@
     'browser/tab_contents/web_drag_dest_win.cc',
     'browser/tab_contents/web_drag_dest_win.h',
     'browser/tab_contents/web_drag_source_gtk.cc',
     'browser/tab_contents/web_drag_source_gtk.h',
     'browser/tab_contents/web_drag_source_mac.h',
     'browser/tab_contents/web_drag_source_mac.mm',
     'browser/tab_contents/web_drag_source_win.cc',
     'browser/tab_contents/web_drag_source_win.h',
     'browser/tab_contents/web_drag_utils_win.cc',
     'browser/tab_contents/web_drag_utils_win.h',
-    'browser/trace_controller.cc',
-    'browser/trace_controller.h',
+    'browser/trace_controller_impl.cc',
+    'browser/trace_controller_impl.h',
     'browser/trace_message_filter.cc',
     'browser/trace_message_filter.h',
     'browser/trace_subscriber_stdio.cc',
     'browser/trace_subscriber_stdio.h',
     'browser/user_metrics.cc',
     'browser/utility_process_host_impl.cc',
     'browser/utility_process_host_impl.h',
     'browser/webui/web_ui_impl.cc',
     'browser/webui/web_ui_impl.h',
     'browser/webui/web_ui_message_handler.cc',
@@ skipping 207 matching lines @@
       ],
     }],
     ['input_speech==0', {
       'sources/': [
         ['exclude', '^browser/speech/'],
       ],
     }],
   ],
 }