[sensors] [win] Implement ambient light sensor for Windows platform

device/generic_sensor/platform_sensor_provider_win.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_GENERIC_SENSOR_PLATFORM_SENSOR_PROVIDER_WIN_H_
+#define DEVICE_GENERIC_SENSOR_PLATFORM_SENSOR_PROVIDER_WIN_H_
+
+#include <SensorsApi.h>
+
+#include "base/win/scoped_comptr.h"
+#include "device/generic_sensor/generic_sensor_export.h"
+#include "device/generic_sensor/platform_sensor_provider.h"
+
+namespace base {
+template <typename T>
+struct DefaultSingletonTraits;
+class Thread;
+}
+
+namespace device {
+
+class PlatformSensorReaderWin;
+
+// Implementation of PlatformSensorProvider for Windows platform.
+// PlatformSensorProviderWin is responsible for following tasks:
+// - Starts sensor thread and stops it when there are no active sensors.
+// - Initialises ISensorManager and creates sensor reader on sensor thread.
+// - Constructs PlatformSensorWin on IPC thread and returns it to requester.
+class DEVICE_GENERIC_SENSOR_EXPORT PlatformSensorProviderWin final
+    : public PlatformSensorProvider {
+ public:
+  static PlatformSensorProviderWin* GetInstance();
+
+  // Overrides ISensorManager COM interface provided by the system, used
+  // only for testing purposes.
+  void SetSensorManagerForTesing(

[Lei Zhang, 2016/10/29 05:10:42]

type: ForTesting

[shalamov, 2016/10/31 13:12:57]

Done.

+      base::win::ScopedComPtr<ISensorManager> sensor_manager);
+
+ protected:
+  ~PlatformSensorProviderWin() override;
+
+  // PlatformSensorProvider interface implementation.
+  void AllSensorsRemoved() override;
+  void CreateSensorInternal(mojom::SensorType type,
+                            mojo::ScopedSharedBufferMapping mapping,
+                            const CreateSensorCallback& callback) override;
+
+ private:
+  PlatformSensorProviderWin();

[Lei Zhang, 2016/10/29 05:10:42]

separate the ctor for the rest.

[shalamov, 2016/10/31 13:12:57]

Done.

+  bool InitializeSensorManager();
+  bool StartSensorThread();
+  void StopSensorThread();
+  std::unique_ptr<PlatformSensorReaderWin> CreateSensorReader(
+      mojom::SensorType type);
+  void SensorReaderCreated(
+      mojom::SensorType type,
+      mojo::ScopedSharedBufferMapping mapping,
+      const CreateSensorCallback& callback,
+      std::unique_ptr<PlatformSensorReaderWin> sensor_reader);
+
+ private:
+  friend struct base::DefaultSingletonTraits<PlatformSensorProviderWin>;
+
+  base::win::ScopedComPtr<ISensorManager> sensor_manager_;
+  std::unique_ptr<base::Thread> sensor_thread_;
+
+  DISALLOW_COPY_AND_ASSIGN(PlatformSensorProviderWin);
+};
+
+}  // namespace device
+
+#endif  // DEVICE_GENERIC_SENSOR_PLATFORM_SENSOR_PROVIDER_WIN_H_