Remove content::BrowserThread knowledge from Device Sensors

content/browser/device_sensors/device_sensor_host.cc

 // Copyright 2016 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 "content/browser/device_sensors/device_sensor_host.h"
 
+#include "base/message_loop/message_loop.h"
 #include "content/browser/device_sensors/device_sensor_service.h"
-#include "content/public/browser/browser_thread.h"
 #include "mojo/public/cpp/bindings/strong_binding.h"
 
 namespace content {
 
 template <typename MojoInterface, ConsumerType consumer_type>
 void DeviceSensorHost<MojoInterface, consumer_type>::Create(
     mojo::InterfaceRequest<MojoInterface> request) {
   mojo::MakeStrongBinding(
       base::WrapUnique(new DeviceSensorHost<MojoInterface, consumer_type>),
       std::move(request));
 }
 
 template <typename MojoInterface, ConsumerType consumer_type>
 DeviceSensorHost<MojoInterface, consumer_type>::DeviceSensorHost()
     : is_started_(false) {
-  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  DCHECK(base::MessageLoopForIO::IsCurrent());
+  DeviceSensorService::GetInstance()->InitOnIOThread();
 }
 
 template <typename MojoInterface, ConsumerType consumer_type>
 DeviceSensorHost<MojoInterface, consumer_type>::~DeviceSensorHost() {
   DCHECK(thread_checker_.CalledOnValidThread());
   if (is_started_)
     DeviceSensorService::GetInstance()->RemoveConsumer(consumer_type);
 }
 
 template <typename MojoInterface, ConsumerType consumer_type>
@@ skipping 23 matching lines @@
 template class DeviceSensorHost<device::mojom::LightSensor,
                                 CONSUMER_TYPE_LIGHT>;
 template class DeviceSensorHost<device::mojom::MotionSensor,
                                 CONSUMER_TYPE_MOTION>;
 template class DeviceSensorHost<device::mojom::OrientationSensor,
                                 CONSUMER_TYPE_ORIENTATION>;
 template class DeviceSensorHost<device::mojom::OrientationAbsoluteSensor,
                                 CONSUMER_TYPE_ORIENTATION_ABSOLUTE>;
 
 }  // namespace content