Adding pref to store the user-selected proximity threshold.

components/proximity_auth/proximity_monitor_impl.h

 // Copyright 2015 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 COMPONENTS_PROXIMITY_AUTH_PROXIMITY_MONITOR_IMPL_H
 #define COMPONENTS_PROXIMITY_AUTH_PROXIMITY_MONITOR_IMPL_H
 
 #include <memory>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
 #include "components/cryptauth/connection.h"
 #include "components/cryptauth/remote_device.h"
 #include "components/proximity_auth/proximity_monitor.h"
 #include "device/bluetooth/bluetooth_device.h"
 
+class PrefService;
+
 namespace base {
 class TickClock;
 }
 
 namespace device {
 class BluetoothAdapter;
 }
 
 namespace proximity_auth {
 
 class ProximityMonitorObserver;
 
 // The concrete implemenation of the proximity monitor interface.
 class ProximityMonitorImpl : public ProximityMonitor {
  public:
   // The |connection| is not owned, and must outlive |this| instance.
   ProximityMonitorImpl(cryptauth::Connection* connection,
-                       std::unique_ptr<base::TickClock> clock);
+                       std::unique_ptr<base::TickClock> clock,
+                       PrefService* pref_service);
   ~ProximityMonitorImpl() override;
 
   // ProximityMonitor:
   void Start() override;
   void Stop() override;
   bool IsUnlockAllowed() const override;
   void RecordProximityMetricsOnAuthSuccess() override;
   void AddObserver(ProximityMonitorObserver* observer) override;
   void RemoveObserver(ProximityMonitorObserver* observer) override;
 
@@ skipping 28 matching lines @@
 
   // Updates the proximity state with a new |connection_info| sample of the
   // current RSSI.
   void AddSample(
       const device::BluetoothDevice::ConnectionInfo& connection_info);
 
   // Checks whether the proximity state has changed based on the current
   // samples. Notifies |observers_| on a change.
   void CheckForProximityStateChange();
 
+  // Gets the user-selected proximity threshold and converts it to a
+  // RSSI value.
+  void GetRssiThresholdFromPrefs();
+
   // The current connection being monitored. Not owned and must outlive this
   // instance.
   cryptauth::Connection* connection_;
 
   // The observers attached to the ProximityMonitor.
   base::ObserverList<ProximityMonitorObserver> observers_;
 
   // The Bluetooth adapter that will be polled for connection info.
   scoped_refptr<device::BluetoothAdapter> bluetooth_adapter_;
 
   // Whether the remote device is currently in close proximity to the local
   // device.
   bool remote_device_is_in_proximity_;
 
   // Whether the proximity monitor is active, i.e. should possibly be scanning
   // for proximity to the remote device.
   bool is_active_;
 
+  // When the RSSI is below this value the phone the unlock is not allowed.
+  int rssi_threshold_;
+
   // The exponentailly weighted rolling average of the RSSI, used to smooth the
   // RSSI readings. Null if the monitor is inactive, has not recently observed
   // an RSSI reading, or the most recent connection info included an invalid
   // measurement.
   std::unique_ptr<double> rssi_rolling_average_;
 
   // Used to access non-decreasing time measurements.
   std::unique_ptr<base::TickClock> clock_;
 
+  // Contains perferences that outlive the lifetime of this object and across
+  // process restarts. Not owned and must outlive this instance.
+  PrefService* pref_service_;
+
   // Used to vend weak pointers for polling. Using a separate factory for these
   // weak pointers allows the weak pointers to be invalidated when polling
   // stops, which effectively cancels the scheduled tasks.
   base::WeakPtrFactory<ProximityMonitorImpl> polling_weak_ptr_factory_;
 
   // Used to vend all other weak pointers.
   base::WeakPtrFactory<ProximityMonitorImpl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ProximityMonitorImpl);
 };
 
 }  // namespace proximity_auth
 
 #endif  // COMPONENTS_PROXIMITY_AUTH_PROXIMITY_MONITOR_IMPL_H