Add missing IWYU message_loop.h includes.

device/geolocation/network_location_provider_unittest.cc

 // Copyright (c) 2012 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 "device/geolocation/network_location_provider.h"
 
 #include <stddef.h>
 
 #include <memory>
 #include <string>
 #include <utility>
 #include <vector>
 
 #include "base/json/json_reader.h"
 #include "base/json/json_writer.h"
 #include "base/macros.h"
+#include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/values.h"
 #include "device/geolocation/fake_access_token_store.h"
 #include "device/geolocation/location_arbitrator.h"
 #include "device/geolocation/wifi_data_provider.h"
 #include "net/base/net_errors.h"
@@ skipping 527 matching lines @@
       EXPECT_TRUE(cache.FindPosition(CreateReferenceWifiScanData(1)));
     } else {
       const int evicted = i - kCacheSize;
       EXPECT_FALSE(cache.FindPosition(CreateReferenceWifiScanData(evicted)));
       EXPECT_TRUE(cache.FindPosition(CreateReferenceWifiScanData(evicted + 1)));
     }
   }
 }
 
 }  // namespace device