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

device/generic_sensor/relative_orientation_fusion_algorithm_using_accelerometer.h

Index: device/generic_sensor/relative_orientation_fusion_algorithm_using_accelerometer.h
diff --git a/device/generic_sensor/relative_orientation_fusion_algorithm_using_accelerometer.h b/device/generic_sensor/relative_orientation_fusion_algorithm_using_accelerometer.h
new file mode 100644
index 0000000000000000000000000000000000000000..4520b764ad6df3f4dcde9998d5666953dd7ad858
--- /dev/null
+++ b/device/generic_sensor/relative_orientation_fusion_algorithm_using_accelerometer.h
@@ -0,0 +1,31 @@
+// 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_RELATIVE_ORIENTATION_FUSION_ALGORITHM_USING_ACCELEROMETER_H_
+#define DEVICE_GENERIC_SENSOR_RELATIVE_ORIENTATION_FUSION_ALGORITHM_USING_ACCELEROMETER_H_
+
+#include "base/macros.h"
+#include "device/generic_sensor/relative_orientation_fusion_algorithm.h"
+
+namespace device {
+
+class RelativeOrientationFusionAlgorithmUsingAccelerometer
+    : public RelativeOrientationFusionAlgorithm {
+ public:
+  RelativeOrientationFusionAlgorithmUsingAccelerometer();
+  ~RelativeOrientationFusionAlgorithmUsingAccelerometer() override;
+
+  void GetRelativeOrientationData(double* x,
+                                  double* y,
+                                  double* z,
+                                  double* w) override;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(
+      RelativeOrientationFusionAlgorithmUsingAccelerometer);
+};
+
+}  // namespace device
+
+#endif  // DEVICE_GENERIC_SENSOR_RELATIVE_ORIENTATION_FUSION_ALGORITHM_USING_ACCELEROMETER_H_