security: PolicyManager: In checkVerificationPolicy, pass stepCount by value since the reference is not needed to modify the caller's value, and it is copied through to the ValidationRequest constructor.
diff --git a/include/ndn-cpp/security/policy/no-verify-policy-manager.hpp b/include/ndn-cpp/security/policy/no-verify-policy-manager.hpp
index 9bfdd1c..1ee9f75 100644
--- a/include/ndn-cpp/security/policy/no-verify-policy-manager.hpp
+++ b/include/ndn-cpp/security/policy/no-verify-policy-manager.hpp
@@ -47,7 +47,7 @@
    */
   virtual ptr_lib::shared_ptr<ValidationRequest>
   checkVerificationPolicy
-    (const ptr_lib::shared_ptr<Data>& data, const int& stepCount, const OnVerified& onVerified, const OnVerifyFailed& onVerifyFailed);
+    (const ptr_lib::shared_ptr<Data>& data, int stepCount, const OnVerified& onVerified, const OnVerifyFailed& onVerifyFailed);
     
   /**
    * Override to always indicate that the signing certificate name and data name satisfy the signing policy.
diff --git a/include/ndn-cpp/security/policy/policy-manager.hpp b/include/ndn-cpp/security/policy/policy-manager.hpp
index 5b3609d..f84a505 100644
--- a/include/ndn-cpp/security/policy/policy-manager.hpp
+++ b/include/ndn-cpp/security/policy/policy-manager.hpp
@@ -54,7 +54,7 @@
    */
   virtual ptr_lib::shared_ptr<ValidationRequest>
   checkVerificationPolicy
-    (const ptr_lib::shared_ptr<Data>& data, const int& stepCount, const OnVerified& onVerified, const OnVerifyFailed& onVerifyFailed) = 0;
+    (const ptr_lib::shared_ptr<Data>& data, int stepCount, const OnVerified& onVerified, const OnVerifyFailed& onVerifyFailed) = 0;
     
   /**
    * Check if the signing certificate name and data name satisfy the signing policy.
diff --git a/src/security/policy/no-verify-policy-manager.cpp b/src/security/policy/no-verify-policy-manager.cpp
index e49ae75..38cc7fd 100644
--- a/src/security/policy/no-verify-policy-manager.cpp
+++ b/src/security/policy/no-verify-policy-manager.cpp
@@ -31,7 +31,7 @@
     
 shared_ptr<ValidationRequest>
 NoVerifyPolicyManager::checkVerificationPolicy
-  (const shared_ptr<Data>& data, const int& stepCount, const OnVerified& onVerified, const OnVerifyFailed& onVerifyFailed)
+  (const shared_ptr<Data>& data, int stepCount, const OnVerified& onVerified, const OnVerifyFailed& onVerifyFailed)
 { 
   onVerified(data); 
   return shared_ptr<ValidationRequest>();
diff --git a/src/security/policy/validation-request.hpp b/src/security/policy/validation-request.hpp
index d9facc9..386b45d 100644
--- a/src/security/policy/validation-request.hpp
+++ b/src/security/policy/validation-request.hpp
@@ -17,7 +17,7 @@
 public:
   ValidationRequest
     (const ptr_lib::shared_ptr<Interest> &interest, const OnVerified& onVerified, const OnVerifyFailed& onVerifyFailed,
-     const int& retry, const int& stepCount)
+     int retry, int stepCount)
   : interest_(interest), onVerified_(onVerified), onVerifyFailed_(onVerifyFailed), retry_(retry), stepCount_(stepCount)
   {
   }