Guard hid_service_win.h include with OS_WIN.

device/hid/hid_service.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 "device/hid/hid_service.h"
 
 #include "base/at_exit.h"
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
 #include "base/stl_util.h"
 #include "components/device_event_log/device_event_log.h"
 
 #if defined(OS_LINUX) && defined(USE_UDEV)
 #include "device/hid/hid_service_linux.h"
 #elif defined(OS_MACOSX)
 #include "device/hid/hid_service_mac.h"
-#else
+#elif defined(OS_WIN)
 #include "device/hid/hid_service_win.h"
 #endif
 
 namespace device {
 
 namespace {
 
 HidService* g_service;
 }
 
@@ skipping 110 matching lines @@
     }
 
     for (const GetDevicesCallback& callback : pending_enumerations_) {
       callback.Run(devices);
     }
     pending_enumerations_.clear();
   }
 }
 
 }  // namespace device