Revert of Move //device/generic_sensor to be part of the internal implementation of the Device Service.

device/generic_sensor/platform_sensor_accelerometer_mac.h

Index: device/generic_sensor/platform_sensor_accelerometer_mac.h
diff --git a/device/generic_sensor/platform_sensor_accelerometer_mac.h b/device/generic_sensor/platform_sensor_accelerometer_mac.h
new file mode 100644
index 0000000000000000000000000000000000000000..02e08b5d1a8dfc992683ae1a2a691b672f73ee1c
--- /dev/null
+++ b/device/generic_sensor/platform_sensor_accelerometer_mac.h
@@ -0,0 +1,55 @@
+// 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_ACCELEROMETER_MAC_H_
+#define DEVICE_GENERIC_SENSOR_PLATFORM_SENSOR_ACCELEROMETER_MAC_H_
+
+#include <memory>
+
+#include "base/timer/timer.h"
+#include "device/generic_sensor/platform_sensor.h"
+
+class SuddenMotionSensor;
+
+namespace device {
+
+// Implementation of PlatformSensor for macOS to query the accelerometer
+// sensor.
+// This is a single instance object per browser process which is created by
+// The singleton PlatformSensorProviderMac. If there are no clients, this
+// instance is not created.
+class PlatformSensorAccelerometerMac : public PlatformSensor {
+ public:
+  // Construct a platform sensor of type ACCELEROMETER, given a buffer |mapping|
+  // where readings will be written.
+  PlatformSensorAccelerometerMac(mojo::ScopedSharedBufferMapping mapping,
+                                 PlatformSensorProvider* provider);
+
+  mojom::ReportingMode GetReportingMode() override;
+  // Can only be called once, the first time or after a StopSensor call.
+  bool StartSensor(const PlatformSensorConfiguration& configuration) override;
+  void StopSensor() override;
+
+ protected:
+  ~PlatformSensorAccelerometerMac() override;
+  bool CheckSensorConfiguration(
+      const PlatformSensorConfiguration& configuration) override;
+  PlatformSensorConfiguration GetDefaultConfiguration() override;
+
+ private:
+  void PollForData();
+
+  std::unique_ptr<SuddenMotionSensor> sudden_motion_sensor_;
+
+  SensorReading reading_;
+
+  // Repeating timer for data polling.
+  base::RepeatingTimer timer_;
+
+  DISALLOW_COPY_AND_ASSIGN(PlatformSensorAccelerometerMac);
+};
+
+}  // namespace device
+
+#endif  // DEVICE_GENERIC_SENSOR_PLATFORM_SENSOR_ACCELEROMETER_MAC_H_