[Sensors] Align sensor reading attribute implementation with the specification

third_party/WebKit/Source/modules/sensor/Sensor.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 Sensor_h
 #define Sensor_h
 
 #include "bindings/core/v8/ActiveScriptWrappable.h"
 #include "bindings/core/v8/ScriptWrappable.h"
 #include "core/dom/ActiveDOMObject.h"
@@ skipping 48 matching lines @@
   // ActiveScriptWrappable overrides.
   bool hasPendingActivity() const override;
 
   DECLARE_VIRTUAL_TRACE();
 
  protected:
   Sensor(ScriptState*,
          const SensorOptions&,
          ExceptionState&,
          device::mojom::blink::SensorType);
-  virtual SensorReading* createSensorReading(SensorProxy*) = 0;
+  virtual std::unique_ptr<SensorReadingFactory>
+  createSensorReadingFactory() = 0;
 
   using SensorConfigurationPtr = device::mojom::blink::SensorConfigurationPtr;
   using SensorConfiguration = device::mojom::blink::SensorConfiguration;
   virtual SensorConfigurationPtr createSensorConfig(
       const SensorOptions&,
       const SensorConfiguration& defaultConfiguration) = 0;
 
  private:
   void initSensorProxyIfNeeded();
 
@@ skipping 24 matching lines @@
                    const String& sanitizedMessage = String(),
                    const String& unsanitizedMessage = String());
 
   void updatePollingStatus();
 
   void notifySensorReadingChanged();
   void notifyStateChanged();
   void notifyError(DOMException* error);
 
  private:
-  Member<SensorReading> m_sensorReading;
   SensorOptions m_sensorOptions;
   device::mojom::blink::SensorType m_type;
   SensorState m_state;
   Member<SensorProxy> m_sensorProxy;
   std::unique_ptr<SensorPollingStrategy> m_polling;
-  SensorProxy::Reading m_storedData;
+  device::SensorReading m_storedData;
   SensorConfigurationPtr m_configuration;
 };
 
 }  // namespace blink
 
 #endif  // Sensor_h