WIP : Generic Sensor API implementation

device/sensors/sensor.mojom

+// 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.
+
+module device.sensors;
+
+enum SensorType {
+  FIRST = 1,
+  AMBIENT_LIGHT = FIRST,
+  PROXIMITY,
+  LINEAR_ACCELERATION,
+  GYROSCOPE,
+  PRESSURE,
+  LAST = PRESSURE // Note: LAST is also equal to the types count.
+};
+
+
+// Sensor reading buffer is putting fields of 64-bit floating point type in the following order:
+// 1) timestamp, 2) other fields
+const uint8 kSensorReadingFieldsCount = 4;
+const uint8 kSensorReadingFieldSize = 8;
+
+struct SensorConfiguration {
+  double frequency;
+  // TODO(shalamov): Add map<string, union> for extra sensor specific configuration.
+};
+
+interface Sensor {
+  SetClient(SensorClient client);
+  Start(SensorConfiguration configuration) => (bool result);
+  Stop(SensorConfiguration configuration) => (bool result);
+};
+
+interface SensorClient {
+  OnSensorError();
+  OnSensorReadingChanged();
+};