include-what-you-use: Fix some tracing-related includes

content/renderer/devtools/v8_sampling_profiler_browsertest.cc

 // Copyright (c) 2014 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 <stddef.h>
 
 #include "base/json/json_reader.h"
+#include "base/memory/ref_counted_memory.h"
 #include "base/run_loop.h"
 #include "base/trace_event/trace_buffer.h"
 #include "base/trace_event/trace_event.h"
 #include "content/public/test/render_view_test.h"
 #include "content/renderer/devtools/v8_sampling_profiler.h"
 
 using base::DictionaryValue;
 using base::ListValue;
 using base::Value;
 using base::trace_event::TraceConfig;
@@ skipping 122 matching lines @@
 }
 
 TEST_F(V8SamplingProfilerTest, V8SamplingSamplesCollected) {
   CollectTrace(0, 1);
   int sample_events_count = CountEvents("V8Sample");
   CHECK_LT(0, sample_events_count);
   base::RunLoop().RunUntilIdle();
 }
 
 }  // namespace content