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

components/tracing/test/trace_event_perftest.cc

 // Copyright 2016 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.
 
 #include "base/bind.h"
 #include "base/memory/ptr_util.h"
 #include "base/memory/ref_counted_memory.h"
 #include "base/pending_task.h"
 #include "base/run_loop.h"
 #include "base/threading/thread.h"
@@ skipping 103 matching lines @@
 TEST_F(TraceEventPerfTest, Create_10000_TracedValue) {
   std::unique_ptr<TracedValue> value;
   {
     ScopedStopwatch value_sw("create_traced_values");
     for (int i = 0; i < 10000; i++) {
       value = MakeTracedValue(i);
     }
   }
 }
 
+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.
   IterableStopwatch trace_sw("events_with_value");
   for (int lap = 0; lap < kNumRuns; lap++) {
     for (int i = 0; i < 10000; i++) {
       TRACE_EVENT_INSTANT1("test_category", "event_with_value",
           TRACE_EVENT_SCOPE_THREAD, "value", MakeTracedValue(i));
     }
     trace_sw.NextLap();
@@ skipping 48 matching lines @@
   EndTraceAndFlush();
 }
 
 TEST_F(TraceEventPerfTest, Submit_10000_TRACE_EVENT0_with_tracing_disabled) {
   ScopedStopwatch stopwatch("events");
   SubmitTraceEvents(10000);
 }
 
 }  // namespace
 }  // namespace tracing