[EasyUnlock] Observe proximity changes and clean up TX power strategy.

components/proximity_auth/unlock_manager_impl.h

Index: components/proximity_auth/unlock_manager_impl.h
diff --git a/components/proximity_auth/unlock_manager_impl.h b/components/proximity_auth/unlock_manager_impl.h
index 104f01b8a8f0f76b18bcef10a3ab9c4f8cb50a60..6049e86ddc2b41460b9ad267391abc643842aed6 100644
--- a/components/proximity_auth/unlock_manager_impl.h
+++ b/components/proximity_auth/unlock_manager_impl.h
@@ -11,6 +11,7 @@
 #include "build/build_config.h"
 #include "components/proximity_auth/messenger_observer.h"
 #include "components/proximity_auth/proximity_auth_system.h"
+#include "components/proximity_auth/proximity_monitor_observer.h"
 #include "components/proximity_auth/remote_device_life_cycle.h"
 #include "components/proximity_auth/remote_status_update.h"
 #include "components/proximity_auth/screenlock_bridge.h"
@@ -32,6 +33,7 @@ class ProximityMonitor;
 // the authentication status of the registered remote devices.
 class UnlockManagerImpl : public UnlockManager,
                           public MessengerObserver,
+                          public ProximityMonitorObserver,
                           public ScreenlockBridge::Observer,
 #if defined(OS_CHROMEOS)
                           chromeos::PowerManagerClient::Observer,
@@ -73,6 +75,9 @@ class UnlockManagerImpl : public UnlockManager,
   void OnUnlockResponse(bool success) override;
   void OnDisconnected() override;
 
+  // ProximityMonitorObserver:
+  void OnProximityStateChanged() override;
+
   // ScreenlockBridge::Observer
   void OnScreenDidLock(
       ScreenlockBridge::LockHandler::ScreenType screen_type) override;