[Sensors] Improvements in fetching reading for sensors with continuous reporting mode

third_party/WebKit/Source/modules/sensor/SensorPollingStrategy.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 SensorPollingStrategy_h
-#define SensorPollingStrategy_h
-
-#include "device/generic_sensor/public/interfaces/sensor_provider.mojom-blink.h"
-#include "platform/Timer.h"
-#include "platform/heap/Handle.h"
-#include "wtf/Functional.h"
-
-namespace blink {
-
-// This class provides different polling behaviour depending on
-// the given 'ReportingMode':
-// - for 'CONTINUOUS' mode the polling function is invoked periodically
-//   with the given polling period (on timer event).
-// - for 'ONCHANGE' mode the polling function is invoked only after client
-//   calls 'onSensorReadingChanged()' however considering the given polling
-//   period: guaranteed not to be called more often than expected.
-class SensorPollingStrategy {
- public:
-  static std::unique_ptr<SensorPollingStrategy> create(
-      double pollingPeriod,
-      std::unique_ptr<Function<void()>> pollFunc,
-      device::mojom::blink::ReportingMode);
-
-  virtual void onSensorReadingChanged() {}
-  virtual void startPolling() = 0;
-  virtual void stopPolling() = 0;
-
-  virtual ~SensorPollingStrategy();
-
- protected:
-  SensorPollingStrategy(double pollingPeriod,
-                        std::unique_ptr<Function<void()>>);
-  virtual void pollForData(TimerBase*) = 0;
-
-  double m_pollingPeriod;
-  std::unique_ptr<Function<void()>> m_pollFunc;
-  Timer<SensorPollingStrategy> m_timer;
-};
-
-}  // namespace blink
-
-#endif  // SensorPollingStrategy_h