[sensors] [mac] Implement ambient light sensor for macOS

device/generic_sensor/platform_sensor_provider_mac.h

Index: device/generic_sensor/platform_sensor_provider_mac.h
diff --git a/device/generic_sensor/platform_sensor_provider_mac.h b/device/generic_sensor/platform_sensor_provider_mac.h
new file mode 100644
index 0000000000000000000000000000000000000000..2c06c2d9b6ba3851cbd8e50a7cca157e586db171
--- /dev/null
+++ b/device/generic_sensor/platform_sensor_provider_mac.h
@@ -0,0 +1,38 @@
+// 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_MAC_H_
+#define DEVICE_GENERIC_SENSOR_PLATFORM_SENSOR_PROVIDER_MAC_H_
+
+#include "device/generic_sensor/platform_sensor_provider.h"
+
+namespace base {
+class Thread;
+}
+
+namespace device {
+
+class SensorsPollingThreadMac;
+
+class PlatformSensorProviderMac : public PlatformSensorProvider {
+ public:
+  PlatformSensorProviderMac();
+  ~PlatformSensorProviderMac() override;
+
+  static PlatformSensorProviderMac* GetInstance();
+
+ protected:
+  scoped_refptr<PlatformSensor> CreateSensorInternal(
+      mojom::SensorType type,
+      mojo::ScopedSharedBufferMapping mapping,
+      uint64_t buffer_size) override;
+
+ private:
+  std::unique_ptr<base::Thread> polling_thread_;
+  DISALLOW_COPY_AND_ASSIGN(PlatformSensorProviderMac);
+};
+
+}  // namespace device
+
+#endif  // DEVICE_GENERIC_SENSOR_PLATFORM_SENSOR_PROVIDER_MAC_H_