Open IOHIDDevices on the FILE thread

device/hid/hid_connection_mac.cc

 // Copyright (c) 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_connection_mac.h"
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/mac/foundation_util.h"
 #include "base/numerics/safe_math.h"
 #include "base/single_thread_task_runner.h"
 #include "base/strings/stringprintf.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "components/device_event_log/device_event_log.h"
 #include "device/hid/hid_connection_mac.h"
 
 namespace device {
 
 namespace {
 
 std::string HexErrorCode(IOReturn error_code) {
   return base::StringPrintf("0x%04x", error_code);
 }
 
 }  // namespace
 
 HidConnectionMac::HidConnectionMac(
-    IOHIDDeviceRef device,
+    base::ScopedCFTypeRef<IOHIDDeviceRef> device,
     scoped_refptr<HidDeviceInfo> device_info,
     scoped_refptr<base::SingleThreadTaskRunner> file_task_runner)
     : HidConnection(device_info),
-      device_(device, base::scoped_policy::RETAIN),
+      device_(std::move(device)),
       file_task_runner_(file_task_runner) {
   task_runner_ = base::ThreadTaskRunnerHandle::Get();
   DCHECK(task_runner_.get());
 
   IOHIDDeviceScheduleWithRunLoop(
       device_.get(), CFRunLoopGetMain(), kCFRunLoopDefaultMode);
 
   size_t expected_report_size = device_info->max_input_report_size();
   if (device_info->has_report_id()) {
     expected_report_size++;
@@ skipping 194 matching lines @@
                                       this,
                                       base::Bind(callback, false)));
   }
 }
 
 void HidConnectionMac::ReturnAsyncResult(const base::Closure& callback) {
   callback.Run();
 }
 
 }  // namespace device