[Sensors] Fix reading updates after page refresh

third_party/WebKit/Source/modules/sensor/SensorProxy.cpp

 // 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.
 
 #include "modules/sensor/SensorProxy.h"
 
 #include "core/dom/Document.h"
 #include "core/frame/LocalFrame.h"
 #include "modules/sensor/SensorProviderProxy.h"
 #include "modules/sensor/SensorReading.h"
 #include "modules/sensor/SensorReadingUpdater.h"
 #include "platform/mojo/MojoHelper.h"
 #include "public/platform/Platform.h"
 
 using namespace device::mojom::blink;
 
 namespace blink {
 
 SensorProxy::SensorProxy(SensorType sensorType,
                          SensorProviderProxy* provider,
-                         Document* document,
+                         Page* page,
                          std::unique_ptr<SensorReadingFactory> readingFactory)
-    : PageVisibilityObserver(document->page()),
+    : PageVisibilityObserver(page),
       m_type(sensorType),
       m_mode(ReportingMode::CONTINUOUS),
       m_provider(provider),
       m_clientBinding(this),
       m_state(SensorProxy::Uninitialized),
       m_suspended(false),
-      m_document(document),
       m_readingFactory(std::move(readingFactory)),
       m_maximumFrequency(0.0) {}
 
 SensorProxy::~SensorProxy() {}
 
 void SensorProxy::dispose() {
   m_clientBinding.Close();
 }
 
 DEFINE_TRACE(SensorProxy) {
-  visitor->trace(m_document);
   visitor->trace(m_readingUpdater);
   visitor->trace(m_reading);
   visitor->trace(m_observers);
   visitor->trace(m_provider);
   PageVisibilityObserver::trace(visitor);
 }
 
 void SensorProxy::addObserver(Observer* observer) {
   if (!m_observers.contains(observer))
     m_observers.insert(observer);
@@ skipping 61 matching lines @@
 
   if (isActive())
     m_readingUpdater->start();
 }
 
 const SensorConfiguration* SensorProxy::defaultConfig() const {
   DCHECK(isInitialized());
   return m_defaultConfig.get();
 }
 
+Document* SensorProxy::document() const {
+  return m_provider->supplementable()->document();
+}
+
 void SensorProxy::updateSensorReading() {
   DCHECK(isInitialized());
   DCHECK(m_readingFactory);
   int readAttempts = 0;
   const int kMaxReadAttemptsCount = 10;
   device::SensorReading readingData;
   while (!tryReadFromBuffer(readingData)) {
     if (++readAttempts == kMaxReadAttemptsCount) {
       handleSensorError();
       return;
@@ skipping 139 matching lines @@
   const device::OneWriterSeqLock& seqlock = buffer->seqlock.value();
   auto version = seqlock.ReadBegin();
   auto readingData = buffer->reading;
   if (seqlock.ReadRetry(version))
     return false;
   result = readingData;
   return true;
 }
 
 }  // namespace blink