generic sensor: Fix class name in SensorImpl comment.

The class is called PlatformSensor, not Sensor. No functional changes.

TBR=reillyg

Change-Id: I6cffc3b41190a34aab8fa0b56d79d101851f0c8f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2409281Reviewed-by: Raphael Kubo da Costa <raphael.kubo.da.costa@intel.com>
Commit-Queue: Raphael Kubo da Costa <raphael.kubo.da.costa@intel.com>
Cr-Commit-Position: refs/heads/master@{#806610}

services/device/generic_sensor/sensor_impl.h

@@ -34,7 +34,7 @@ class SensorImpl final : public mojom::Sensor, public PlatformSensor::Client {
   void Resume() override;
   void ConfigureReadingChangeNotifications(bool enabled) override;
 
-  // device::Sensor::Client implementation.
+  // device::PlatformSensor::Client implementation.
   void OnSensorReadingChanged(mojom::SensorType type) override;
   void OnSensorError() override;
   bool IsSuspended() override;