[Sensors] Improvements in shared buffer managing

device/generic_sensor/fake_platform_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 DEVICE_GENERIC_SENSOR_FAKE_PLATFORM_SENSOR_H_
 #define DEVICE_GENERIC_SENSOR_FAKE_PLATFORM_SENSOR_H_
 
 #include "device/generic_sensor/platform_sensor.h"
 
 namespace device {
 
 class FakePlatformSensor : public PlatformSensor {
  public:
   FakePlatformSensor(mojom::SensorType type,
                      mojo::ScopedSharedBufferMapping mapping,
-                     uint64_t buffer_size,
-                     PlatformSensorProvider* provider);
+                     PlatformSensorProvider* provider,
+                     scoped_refptr<base::SingleThreadTaskRunner> task_runner);
 
   mojom::ReportingMode GetReportingMode() override;
   PlatformSensorConfiguration GetDefaultConfiguration() override;
 
   bool started() const { return started_; }
 
   using PlatformSensor::NotifySensorReadingChanged;
   using PlatformSensor::NotifySensorError;
   using PlatformSensor::config_map;
 
@@ skipping 10 matching lines @@
   PlatformSensorConfiguration config_;
 
   bool started_;
 
   DISALLOW_COPY_AND_ASSIGN(FakePlatformSensor);
 };
 
 }  // namespace device
 
 #endif  // DEVICE_GENERIC_SENSOR_FAKE_PLATFORM_SENSOR_H