[Sensors] Improvements in shared buffer managing

device/generic_sensor/sensor_provider_impl.cc

Index: device/generic_sensor/sensor_provider_impl.cc
diff --git a/device/generic_sensor/sensor_provider_impl.cc b/device/generic_sensor/sensor_provider_impl.cc
index 2cdb1c5a32d5b32ac3c3b97070d0a3a2f0983d33..c1c88963dd564ab6306ed780517fee04318ba536 100644
--- a/device/generic_sensor/sensor_provider_impl.cc
+++ b/device/generic_sensor/sensor_provider_impl.cc
@@ -12,16 +12,6 @@
 
 namespace device {
 
-namespace {
-
-uint64_t GetBufferOffset(mojom::SensorType type) {
-  return (static_cast<uint64_t>(mojom::SensorType::LAST) -
-          static_cast<uint64_t>(type)) *
-         mojom::SensorInitParams::kReadBufferSize;
-}
-
-}  // namespace
-
 // static
 void SensorProviderImpl::Create(mojom::SensorProviderRequest request) {
   PlatformSensorProvider* provider = PlatformSensorProvider::GetInstance();
@@ -49,8 +39,7 @@ void SensorProviderImpl::GetSensor(mojom::SensorType type,
 
   scoped_refptr<PlatformSensor> sensor = provider_->GetSensor(type);
   if (!sensor) {
-    sensor = provider_->CreateSensor(
-        type, mojom::SensorInitParams::kReadBufferSize, GetBufferOffset(type));
+    sensor = provider_->CreateSensor(type);
   }
 
   if (!sensor) {
@@ -62,7 +51,7 @@ void SensorProviderImpl::GetSensor(mojom::SensorType type,
 
   auto init_params = mojom::SensorInitParams::New();
   init_params->memory = std::move(cloned_handle);
-  init_params->buffer_offset = GetBufferOffset(type);
+  init_params->buffer_offset = provider_->GetSharedBufferOffset(type);
   init_params->mode = sensor->GetReportingMode();
   init_params->default_configuration = sensor->GetDefaultConfiguration();