[NOT FOR REVIEW] Tracing performance assessment for task profiler.

components/tracing/test/trace_event_perftest.cc

Index: components/tracing/test/trace_event_perftest.cc
diff --git a/components/tracing/test/trace_event_perftest.cc b/components/tracing/test/trace_event_perftest.cc
index 721c3aa43f9e781debcd923c4619fc3bf6609913..c1cccc5fc616e195ebb10d405086bbe28c530b9b 100644
--- a/components/tracing/test/trace_event_perftest.cc
+++ b/components/tracing/test/trace_event_perftest.cc
@@ -121,6 +121,16 @@ TEST_F(TraceEventPerfTest, Create_10000_TracedValue) {
   }
 }
 
+TEST_F(TraceEventPerfTest, Create_10M_TracedValue) {
+  std::unique_ptr<TracedValue> value;
+  {
+    ScopedStopwatch value_sw("create_traced_values");
+    for (int i = 0; i < 10000000; i++) {
+      value = MakeTracedValue(i);
+    }
+  }
+}
+
 TEST_F(TraceEventPerfTest, Submit_10000_TRACE_EVENT_with_TracedValue) {
   BeginTrace();
   // Time reported by this timer includes TracedValue creation as well.