Slow Reports - Add message filter to trigger background traces from child processes.

content/browser/tracing/tracing_controller_impl.h

 // Copyright (c) 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.
 
 #ifndef CONTENT_BROWSER_TRACING_TRACING_CONTROLLER_IMPL_H_
 #define CONTENT_BROWSER_TRACING_TRACING_CONTROLLER_IMPL_H_
 
 #include <set>
 #include <string>
 #include <vector>
@@ skipping 43 matching lines @@
 
   void RegisterTracingUI(TracingUI* tracing_ui);
   void UnregisterTracingUI(TracingUI* tracing_ui);
 
   // base::trace_event::MemoryDumpManagerDelegate implementation.
   void RequestGlobalMemoryDump(
       const base::trace_event::MemoryDumpRequestArgs& args,
       const base::trace_event::MemoryDumpCallback& callback) override;
   bool IsCoordinatorProcess() const override;
 
- private:
+  typedef base::Callback<void(TraceMessageFilter*)>
+      TraceMessageFilterAddedCallback;
   typedef std::set<scoped_refptr<TraceMessageFilter> > TraceMessageFilterSet;
 
+  TraceMessageFilterAddedCallback trace_filter_added_callback_;
+  void SetTraceMessageFilterAddedCallback(
+      const TraceMessageFilterAddedCallback& callback);
+  void GetTraceMessageFilters(TraceMessageFilterSet*);
+
+ private:
   friend struct base::DefaultLazyInstanceTraits<TracingControllerImpl>;
   friend class TraceMessageFilter;
 
   TracingControllerImpl();
   ~TracingControllerImpl() override;
 
   bool can_enable_recording() const {
     return !is_recording_;
   }
 
@@ skipping 105 matching lines @@
   bool is_recording_;
   bool is_monitoring_;
 
   GetCategoriesDoneCallback pending_get_categories_done_callback_;
   GetTraceBufferUsageCallback pending_trace_buffer_usage_callback_;
 
   std::string watch_category_name_;
   std::string watch_event_name_;
   WatchEventCallback watch_event_callback_;
 
+  TraceMessageFilterAddedCallback trace_message_filter_added_callback_;
+
   std::set<std::string> known_category_groups_;
   std::set<TracingUI*> tracing_uis_;
   scoped_refptr<TraceDataSink> trace_data_sink_;
   scoped_refptr<TraceDataSink> monitoring_data_sink_;
 
   DISALLOW_COPY_AND_ASSIGN(TracingControllerImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_TRACING_TRACING_CONTROLLER_IMPL_H_