Add RELATIVE_ORIENTATION sensor implementation on macOS to //device/generic_sensor

device/generic_sensor/platform_sensor_fusion_relative_orientation.h

Index: device/generic_sensor/platform_sensor_fusion_relative_orientation.h
diff --git a/device/generic_sensor/platform_sensor_fusion_relative_orientation.h b/device/generic_sensor/platform_sensor_fusion_relative_orientation.h
new file mode 100644
index 0000000000000000000000000000000000000000..75bae74be6e7d03464cb8f14c706b5ee7c5fc844
--- /dev/null
+++ b/device/generic_sensor/platform_sensor_fusion_relative_orientation.h
@@ -0,0 +1,64 @@
+// Copyright 2017 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.
+
+#ifndef DEVICE_GENERIC_SENSOR_PLATFORM_SENSOR_FUSION_RELATIVE_ORIENTATION_H_
+#define DEVICE_GENERIC_SENSOR_PLATFORM_SENSOR_FUSION_RELATIVE_ORIENTATION_H_
+
+#include <memory>
+
+#include "base/macros.h"
+#include "base/timer/timer.h"
+#include "device/generic_sensor/platform_sensor.h"
+#include "device/generic_sensor/platform_sensor_provider_base.h"
+
+namespace device {
+
+class RelativeOrientationFusionAlgorithm;
+
+// Implementation of relative orientation PlatformSensor using fusion.
+// This is a single instance object per browser process which is created by
+// The singleton PlatformSensorProvider. If there are no clients, this instance
+// is not created.
+class PlatformSensorFusionRelativeOrientation : public PlatformSensor,
+                                                public PlatformSensor::Client {
+ public:
+  // Construct a platform fusion sensor of type RELATIVE_ORIENTATION, given a
+  // buffer |mapping| where readings will be written.
+  PlatformSensorFusionRelativeOrientation(
+      mojo::ScopedSharedBufferMapping mapping,
+      PlatformSensorProvider* provider,
+      const PlatformSensorProviderBase::CreateSensorCallback& callback);
+
+  // PlatformSensor:
+  mojom::ReportingMode GetReportingMode() override;
+  PlatformSensorConfiguration GetDefaultConfiguration() override;
+  // Can only be called once, the first time or after a StopSensor call.
+  bool StartSensor(const PlatformSensorConfiguration& configuration) override;
+  void StopSensor() override;
+  bool CheckSensorConfiguration(
+      const PlatformSensorConfiguration& configuration) override;
+
+  // PlatformSensor::Client:
+  void OnSensorReadingChanged() override;
+  void OnSensorError() override;
+  bool IsNotificationSuspended() override;
+
+ protected:
+  ~PlatformSensorFusionRelativeOrientation() override;
+
+ private:
+  void CreateAccelerometerCallback(scoped_refptr<PlatformSensor> accelerometer);
+  void CreateAccelerometerSucceeded();
+
+  PlatformSensorProviderBase::CreateSensorCallback callback_;
+  SensorReading reading_;
+  scoped_refptr<PlatformSensor> accelerometer_;
+  std::unique_ptr<RelativeOrientationFusionAlgorithm> fusion_algorithm_;
+
+  DISALLOW_COPY_AND_ASSIGN(PlatformSensorFusionRelativeOrientation);
+};
+
+}  // namespace device
+
+#endif  // DEVICE_GENERIC_SENSOR_PLATFORM_SENSOR_FUSION_RELATIVE_ORIENTATION_H_