Convert //components/proximity_auth from scoped_ptr to std::unique_ptr

components/proximity_auth/remote_device_loader.h

Index: components/proximity_auth/remote_device_loader.h
diff --git a/components/proximity_auth/remote_device_loader.h b/components/proximity_auth/remote_device_loader.h
index 17229aab4636675652f7beeddef43e33c7698589..d60cc4b4050e9bf3dc135bdbe6af0af49db99f34 100644
--- a/components/proximity_auth/remote_device_loader.h
+++ b/components/proximity_auth/remote_device_loader.h
@@ -5,11 +5,11 @@
 #ifndef COMPONENTS_PROXIMITY_REMOTE_DEVICE_LOADER_H
 #define COMPONENTS_PROXIMITY_REMOTE_DEVICE_LOADER_H
 
+#include <memory>
 #include <string>
 
 #include "base/callback.h"
 #include "base/macros.h"
-#include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "components/proximity_auth/cryptauth/proto/cryptauth_api.pb.h"
 #include "components/proximity_auth/remote_device.h"
@@ -34,7 +34,7 @@ class RemoteDeviceLoader {
       const std::vector<cryptauth::ExternalDeviceInfo>& unlock_keys,
       const std::string& user_id,
       const std::string& user_private_key,
-      scoped_ptr<SecureMessageDelegate> secure_message_delegate,
+      std::unique_ptr<SecureMessageDelegate> secure_message_delegate,
       ProximityAuthPrefManager* pref_manager);
 
   ~RemoteDeviceLoader();
@@ -59,7 +59,7 @@ class RemoteDeviceLoader {
   const std::string user_private_key_;
 
   // Performs the PSK key derivation.
-  scoped_ptr<SecureMessageDelegate> secure_message_delegate_;
+  std::unique_ptr<SecureMessageDelegate> secure_message_delegate_;
 
   // Used to retrieve the address for BLE devices. Not owned.
   ProximityAuthPrefManager* pref_manager_;