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

content/browser/media/webrtc_getusermedia_browsertest.cc

 // Copyright 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/command_line.h"
 #include "base/json/json_reader.h"
+#include "base/memory/ref_counted_memory.h"
 #include "base/strings/stringprintf.h"
 #include "base/test/trace_event_analyzer.h"
 #include "base/trace_event/trace_event_impl.h"
 #include "base/values.h"
 #include "build/build_config.h"
 #include "content/browser/media/webrtc_internals.h"
 #include "content/browser/web_contents/web_contents_impl.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/test/browser_test_utils.h"
 #include "content/public/test/content_browser_test_utils.h"
@@ skipping 750 matching lines @@
     {640, 640, 360, 360, 10, 30},
     {640, 640, 480, 480, 10, 30},
     {960, 960, 720, 720, 10, 30},
     {1280, 1280, 720, 720, 10, 30}};
 
 INSTANTIATE_TEST_CASE_P(UserMedia,
                         WebRtcConstraintsBrowserTest,
                         testing::ValuesIn(kAllUserMediaSizes));
 
 }  // namespace content