Add missing IWYU message_loop.h includes.

device/u2f/u2f_hid_device_unittest.cc

 // Copyright 2017 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 <list>
 
 #include "base/bind.h"
 #include "base/memory/ptr_util.h"
+#include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "base/test/test_io_thread.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "device/base/mock_device_client.h"
 #include "device/hid/hid_connection.h"
 #include "device/hid/hid_device_filter.h"
 #include "device/hid/mock_hid_service.h"
 #include "device/test/test_device_client.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ skipping 289 matching lines @@
       U2fApduResponse::CreateFromMessage(std::vector<uint8_t>({0x0, 0x0})));
   device->DeviceTransact(U2fApduCommand::CreateVersion(),
                          base::Bind(&ResponseCallback, &response3));
   EXPECT_EQ(U2fHidDevice::State::DEVICE_ERROR, device->state_);
   EXPECT_EQ(nullptr, response1);
   EXPECT_EQ(nullptr, response2);
   EXPECT_EQ(nullptr, response3);
 };
 
 }  // namespace device