Fix races in trace events filtering.

base/trace_event/trace_log.h

Index: base/trace_event/trace_log.h
diff --git a/base/trace_event/trace_log.h b/base/trace_event/trace_log.h
index 540d7d0bd3e0e06aa910b65cb2850ef08143cc62..3eb79b819f7883acd4147689e8fce68077bc4441 100644
--- a/base/trace_event/trace_log.h
+++ b/base/trace_event/trace_log.h
@@ -403,6 +403,8 @@ class BASE_EXPORT TraceLog : public MemoryDumpProvider {
   void UpdateCategoryGroupEnabledFlags();
   void UpdateCategoryGroupEnabledFlag(size_t category_index);
 
+  void CreateFiltersForTraceConfig();
+
   // Configure synthetic delays based on the values set in the current
   // trace config.
   void UpdateSyntheticDelaysFromTraceConfig();