Add a method for transfering an ownership of captured TraceEvents (#52940)

Summary:
Pull Request resolved: #52940

# Changelog: [Internal]

This is required for storing these Trace Events somewhere outside of PerformanceTracer, in case these events will be dispatched later.

Reviewed By: rubennorte

Differential Revision: D78741192

fbshipit-source-id: 3cc2eacd922855231fafb93c32d326b150b3c19b

Author: hoxyq

packages/react-native/ReactCommon/jsinspector-modern/tracing/PerformanceTracer.cpp

@@ -131,6 +131,15 @@ folly::dynamic PerformanceTracer::collectEvents(uint16_t chunkSize) {
   return chunks;
 }
 
+std::vector<TraceEvent> PerformanceTracer::collectTraceEvents() {
+  std::vector<TraceEvent> events;
+  {
+    std::lock_guard lock(mutex_);
+    buffer_.swap(events);
+  }
+  return events;
+}
+
 void PerformanceTracer::reportMark(
     const std::string_view& name,
     HighResTimeStamp start,

packages/react-native/ReactCommon/jsinspector-modern/tracing/PerformanceTracer.h

@@ -65,6 +65,12 @@ class PerformanceTracer {
    */
   folly::dynamic collectEvents(uint16_t chunkSize);
 
+  /**
+   * Transfers an ownership of all buffered TraceEvents, the local buffer state
+   * is invalidated after this call.
+   */
+  std::vector<TraceEvent> collectTraceEvents();
+
   /**
    * Record a `Performance.mark()` event - a labelled timestamp. If not
    * currently tracing, this is a no-op.