[sensors] Introduce Generic Sensor API interfaces

device/generic_sensor/sensor_impl.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 "device/generic_sensor/sensor_impl.h"
+
+#include <utility>
+
+namespace device {
+
+SensorImpl::SensorImpl(mojo::InterfaceRequest<Sensor> request,
+                       scoped_refptr<PlatformSensor> sensor)
+    : sensor_(std::move(sensor)),
+      binding_(this, std::move(request)),
+      suspended_(false) {
+  sensor_->AddClient(this);
+}
+
+SensorImpl::~SensorImpl() {
+  sensor_->RemoveClient(this);
+}
+
+mojom::SensorClientRequest SensorImpl::GetClient() {
+  return mojo::GetProxy(&client_);
+}
+
+void SensorImpl::AddConfiguration(
+    const PlatformSensorConfiguration& configuration,
+    const AddConfigurationCallback& callback) {
+  // TODO(Mikhail): To avoid overflowing browser by repeated AddConfigs
+  // (maybe limit the number of configs per client).
+  callback.Run(sensor_->StartListening(this, configuration));
+}
+
+void SensorImpl::RemoveConfiguration(
+    const PlatformSensorConfiguration& configuration,
+    const RemoveConfigurationCallback& callback) {
+  callback.Run(sensor_->StopListening(this, configuration));
+}
+
+void SensorImpl::Suspend() {
+  suspended_ = true;
+  sensor_->UpdateSensor();
+}
+
+void SensorImpl::Resume() {
+  suspended_ = false;
+  sensor_->UpdateSensor();
+}
+
+void SensorImpl::OnSensorReadingChanged() {
+  DCHECK(!suspended_);
+  if (client_)
+    client_->SensorReadingChanged();
+}
+
+void SensorImpl::OnSensorError() {
+  DCHECK(!suspended_);
+  if (client_)
+    client_->RaiseError();
+}
+
+bool SensorImpl::IsNotificationSuspended() {
+  return suspended_;
+}
+
+}  // namespace device