[sensors] [win] Fix ambient light not working properly Windows 10.

device/generic_sensor/platform_sensor_reader_win.h

Index: device/generic_sensor/platform_sensor_reader_win.h
diff --git a/device/generic_sensor/platform_sensor_reader_win.h b/device/generic_sensor/platform_sensor_reader_win.h
index 07dd63f37d8726fb32e8c5c0bb277645b94dd78c..9a4c00d90b14f6a53ae5812edf0aa6ad5ef07b95 100644
--- a/device/generic_sensor/platform_sensor_reader_win.h
+++ b/device/generic_sensor/platform_sensor_reader_win.h
@@ -55,6 +55,7 @@ class PlatformSensorReaderWin {
       base::win::ScopedComPtr<ISensorManager> sensor_manager);
 
   bool SetReportingInterval(const PlatformSensorConfiguration& configuration);
+  void ListenSensorEvent();
   HRESULT SensorReadingChanged(ISensorDataReport& report,
                                SensorReading& reading) const;
   void SensorError();
@@ -72,6 +73,7 @@ class PlatformSensorReaderWin {
   Client* client_;
   base::win::ScopedComPtr<ISensor> sensor_;
   scoped_refptr<EventListener> event_listener_;
+  base::WeakPtrFactory<PlatformSensorReaderWin> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(PlatformSensorReaderWin);
 };