[Sensors] Fix reading updates after page refresh

third_party/WebKit/Source/modules/sensor/SensorProxy.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 SensorProxy_h
 #define SensorProxy_h
 
 #include "core/dom/ExceptionCode.h"
 #include "core/page/PageVisibilityObserver.h"
 #include "device/generic_sensor/public/cpp/sensor_reading.h"
@@ skipping 68 matching lines @@
 
   // The |SensorReading| instance which is shared between sensor instances
   // of the same type.
   // Note: the returned value is reset after updateSensorReading() call.
   SensorReading* sensorReading() const { return m_reading; }
 
   const device::mojom::blink::SensorConfiguration* defaultConfig() const;
 
   double maximumFrequency() const { return m_maximumFrequency; }
 
-  Document* document() const { return m_document; }
+  Document* document() const;
   const WTF::Vector<double>& frequenciesUsed() const {
     return m_frequenciesUsed;
   }
 
   DECLARE_VIRTUAL_TRACE();
 
  private:
   friend class SensorProviderProxy;
   friend class SensorReadingUpdaterContinuous;
   friend class SensorReadingUpdaterOnChange;
   SensorProxy(device::mojom::blink::SensorType,
               SensorProviderProxy*,
-              Document*,
+              Page*,
               std::unique_ptr<SensorReadingFactory>);
 
   // Updates sensor reading from shared buffer.
   void updateSensorReading();
   void notifySensorChanged(double timestamp);
 
   // device::mojom::blink::SensorClient overrides.
   void RaiseError() override;
   void SensorReadingChanged() override;
 
@@ skipping 25 matching lines @@
 
   device::mojom::blink::SensorPtr m_sensor;
   device::mojom::blink::SensorConfigurationPtr m_defaultConfig;
   mojo::Binding<device::mojom::blink::SensorClient> m_clientBinding;
 
   enum State { Uninitialized, Initializing, Initialized };
   State m_state;
   mojo::ScopedSharedBufferHandle m_sharedBufferHandle;
   mojo::ScopedSharedBufferMapping m_sharedBuffer;
   bool m_suspended;
-  Member<Document> m_document;
   Member<SensorReading> m_reading;
   std::unique_ptr<SensorReadingFactory> m_readingFactory;
   double m_maximumFrequency;
 
   Member<SensorReadingUpdater> m_readingUpdater;
   WTF::Vector<double> m_frequenciesUsed;
   double m_lastRafTimestamp;
 
   using ReadingBuffer = device::SensorReadingSharedBuffer;
   static_assert(
       sizeof(ReadingBuffer) ==
           device::mojom::blink::SensorInitParams::kReadBufferSizeForTests,
       "Check reading buffer size for tests");
 };
 
 }  // namespace blink
 
 #endif  // SensorProxy_h