Clean up HID backend and API.

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/callback.h"
 #include "base/mac/foundation_util.h"
 #include "base/threading/thread_restrictions.h"
@@ skipping 21 matching lines @@
   CFRetain(device);
   inbound_buffer_.reset((uint8_t*) malloc(device_info.input_report_size + 1));
   IOHIDDeviceRegisterInputReportCallback(
       device_.get(),
       inbound_buffer_.get(),
       device_info.input_report_size + 1,
       &HidConnectionMac::InputReportCallback,
       this);
   IOHIDDeviceOpen(device_, kIOHIDOptionsTypeNone);
 }
+
 HidConnectionMac::~HidConnectionMac() {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   while (read_queue_.size()) {
     read_queue_.front().c.Run(false, 0);
     read_queue_.pop();
   }
 
   IOHIDDeviceClose(device_, kIOHIDOptionsTypeNone);
 }
@@ skipping 127 matching lines @@
                                       0,
                                       (uint8_t*) buffer->data(),
                                       &len);
   if (res == kIOReturnSuccess)
     callback.Run(true, len);
   else
     callback.Run(false, 0);
 }
 
 }  // namespace device