[Sensors] Clamp given sampling frequency to the minimum supported one

device/generic_sensor/platform_sensor.h

Index: device/generic_sensor/platform_sensor.h
diff --git a/device/generic_sensor/platform_sensor.h b/device/generic_sensor/platform_sensor.h
index 62320a5c48dba20754d5cd9080b64ef3df70706e..2df4ade2b055c2e295971f9f386437be9f9415dd 100644
--- a/device/generic_sensor/platform_sensor.h
+++ b/device/generic_sensor/platform_sensor.h
@@ -48,6 +48,10 @@ class DEVICE_GENERIC_SENSOR_EXPORT PlatformSensor
   // The default implementation returns default frequency.
   virtual double GetMaximumSupportedFrequency();
 
+  // Can be overriden to return the sensor minimum sampling frequency.
+  // The default implementation returns '1.0 / (60 * 60)', i.e. once per hour.

[Reilly Grant (use Gerrit), 2017/02/22 18:40:15]

This feels somewhat arbitrary but using
std::numeric_limits<double>::denorm_min() would probably cause problems.

[Mikhail, 2017/02/23 12:42:34]

yeah, ideally we should get the actual values from the platform.

+  virtual double GetMinimumSupportedFrequency();
+
   mojom::SensorType GetType() const;
 
   bool StartListening(Client* client,