[sensors] Introduce Generic Sensor API interfaces

device/generic_sensor/platform_sensor_configuration.h

+// 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.
+
+#ifndef DEVICE_SENSORS_PLATFORM_SENSOR_CONFIGURATION_H_
+#define DEVICE_SENSORS_PLATFORM_SENSOR_CONFIGURATION_H_
+
+#include "base/logging.h"
+#include "device/generic_sensor/sensor_export.h"
+
+namespace device {
+
+class DEVICE_SENSOR_EXPORT PlatformSensorConfiguration {
+ public:
+  PlatformSensorConfiguration();
+  explicit PlatformSensorConfiguration(double frequency);
+  ~PlatformSensorConfiguration();
+
+  bool operator==(const PlatformSensorConfiguration& other) const;
+
+  void set_frequency(double frequency) { frequency_ = frequency; }
+  double frequency() const {
+    DCHECK(frequency_ <= 60.0 && frequency_ > 0.0);

[Reilly Grant (use Gerrit), 2016/08/11 20:59:37]

Do this check in set_frequency so that the call stack shows anyone debugging
this were the bad value came from.

[Mikhail, 2016/08/12 10:21:48]

Done.

+    return frequency_;
+  }
+
+ private:
+  double frequency_;

[Reilly Grant (use Gerrit), 2016/08/11 20:59:37]

Provide a safe default for frequency_ so that the default constructor doesn't
leave it uninitialized.

[Mikhail, 2016/08/12 10:21:48]

Done.

+};
+
+}  // namespace device
+
+#endif  // DEVICE_SENSORS_PLATFORM_SENSOR_CONFIGURATION_H_