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

device/generic_sensor/relative_orientation_fusion_algorithm.h

+// 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_H_
+#define DEVICE_GENERIC_SENSOR_RELATIVE_ORIENTATION_FUSION_ALGORITHM_H_
+
+#include "base/macros.h"
+
+namespace device {
+
+// Base class for relative orientation fusion algorithm.
+// Subclasses can use Accelerometer or Accelerometer + Gyroscope to create
+// a fusion algorithm.
+class RelativeOrientationFusionAlgorithm {
+ public:
+  RelativeOrientationFusionAlgorithm();
+  virtual ~RelativeOrientationFusionAlgorithm();
+
+  void set_acceleration(double acceleration_x,

[timvolodine, 2017/06/21 18:22:11]

think would be good to document the units of acceleration

[juncai, 2017/07/20 00:22:16]

I will update the sensor_reading.h to add units for ACCELEROMETER,
LINEAR_ACCELERATION and GYROSCOPE in a separate CL.

+                        double acceleration_y,
+                        double acceleration_z) {
+    acceleration_x_ = acceleration_x;
+    acceleration_y_ = acceleration_y;
+    acceleration_z_ = acceleration_z;
+  }
+
+  void set_angular_speed(double angular_speed_x,
+                         double angular_speed_y,
+                         double angular_speed_z) {

[timvolodine, 2017/06/21 18:22:11]

this is currently not used? any plans to provide fusion based on both
acceleration and gyroscope

[juncai, 2017/07/20 00:22:16]

A new CL:
https://chromium-review.googlesource.com/c/578253/
adds a general fusion sensor and any combination of fusion algorithm can be
used.
Follow-up CL will implement fusion based on both acceleration and gyroscope.

+    angular_speed_x_ = angular_speed_x;
+    angular_speed_y_ = angular_speed_y;
+    angular_speed_z_ = angular_speed_z;
+  }
+
+  virtual void GetRelativeOrientationData(double* x,
+                                          double* y,
+                                          double* z,
+                                          double* w) = 0;
+
+ protected:
+  double acceleration_x_;
+  double acceleration_y_;
+  double acceleration_z_;
+  double angular_speed_x_;
+  double angular_speed_y_;
+  double angular_speed_z_;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(RelativeOrientationFusionAlgorithm);
+};
+
+}  // namespace device
+
+#endif  // DEVICE_GENERIC_SENSOR_RELATIVE_ORIENTATION_FUSION_ALGORITHM_H_