[Sensors] Improvements in shared buffer managing

device/generic_sensor/platform_sensor.cc

Index: device/generic_sensor/platform_sensor.cc
diff --git a/device/generic_sensor/platform_sensor.cc b/device/generic_sensor/platform_sensor.cc
index bca1fae37f9c6f07d63bd4c62d14b50c622839be..f1c04eace928628058cecd07a1be1ccfb1a1fb78 100644
--- a/device/generic_sensor/platform_sensor.cc
+++ b/device/generic_sensor/platform_sensor.cc
@@ -6,6 +6,7 @@
 
 #include <utility>
 
+#include "base/threading/thread_task_runner_handle.h"
 #include "device/generic_sensor/platform_sensor_provider.h"
 #include "device/generic_sensor/public/cpp/platform_sensor_configuration.h"
 
@@ -80,6 +81,14 @@ void PlatformSensor::RemoveClient(Client* client) {
   }
 }
 
+void PlatformSensor::UpdateSensorReading(const mojom::SensorReading& reading) {
+  ReadingBuffer* buffer =
+      static_cast<ReadingBuffer*>(shared_buffer_mapping_.get());
+  buffer->seqlock.WriteBegin();
+  buffer->data = reading;
+  buffer->seqlock.WriteEnd();
+}
+
 void PlatformSensor::NotifySensorReadingChanged() {
   using ClientsList = decltype(clients_);
   ClientsList::Iterator it(&clients_);