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

extensions/browser/api/display_source/display_source_apitestbase.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 "extensions/browser/api/display_source/display_source_apitestbase.h"
 
+#include <list>
 #include <map>
 #include <utility>
 
 #include "base/memory/ptr_util.h"
 #include "net/base/net_errors.h"
 #include "net/udp/udp_socket.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace extensions {
 
@@ skipping 507 matching lines @@
         base::Bind(&MockDisplaySourceConnectionDelegate::Disconnect,
                    base::Unretained(this), StringCallback()));
     return;
    }
 
   DCHECK(socket_.get());
   ReceiveMediaPacket();
 }
 
 }  // namespace extensions