Remove unused thread.h include in trace_event_impl.h and fix IWUU.

media/cast/test/end2end_unittest.cc

 // Copyright 2013 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.
 //
 // This test generate synthetic data. For audio it's a sinusoid waveform with
 // frequency kSoundFrequency and different amplitudes. For video it's a pattern
 // that is shifting by one pixel per frame, each pixels neighbors right and down
 // is this pixels value +1, since the pixel value is 8 bit it will wrap
 // frequently within the image. Visually this will create diagonally color bands
 // that moves across the screen
 
 #include <math.h>
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
 #include <functional>
 #include <list>
 #include <map>
 #include <utility>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/memory/ptr_util.h"
+#include "base/message_loop/message_loop.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/sys_byteorder.h"
 #include "base/test/simple_test_tick_clock.h"
 #include "base/time/tick_clock.h"
 #include "media/base/audio_bus.h"
 #include "media/base/fake_single_thread_task_runner.h"
 #include "media/base/video_frame.h"
 #include "media/cast/cast_config.h"
 #include "media/cast/cast_environment.h"
 #include "media/cast/cast_receiver.h"
@@ skipping 1235 matching lines @@
       EXPECT_EQ(0u, jump);
       jump = i;
     }
   }
   EXPECT_GT(jump, 49u);
   EXPECT_LT(jump, 120u);
 }
 
 }  // namespace cast
 }  // namespace media