Cleanup: Pass std::string as const reference from media/

media/cast/common/transport_encryption_handler.cc

 // Copyright 2014 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.
 
 #include "media/cast/common/transport_encryption_handler.h"
 
 #include "base/logging.h"
 #include "crypto/encryptor.h"
 #include "crypto/symmetric_key.h"
 #include "media/cast/net/cast_transport_defines.h"
@@ skipping 23 matching lines @@
 }  // namespace
 
 namespace media {
 namespace cast {
 
 TransportEncryptionHandler::TransportEncryptionHandler()
     : key_(), encryptor_(), iv_mask_(), is_activated_(false) {}
 
 TransportEncryptionHandler::~TransportEncryptionHandler() {}
 
-bool TransportEncryptionHandler::Initialize(std::string aes_key,
-                                            std::string aes_iv_mask) {
+bool TransportEncryptionHandler::Initialize(const std::string& aes_key,
+                                            const std::string& aes_iv_mask) {
   is_activated_ = false;
   if (aes_iv_mask.size() == kAesKeySize && aes_key.size() == kAesKeySize) {
     iv_mask_ = aes_iv_mask;
     key_.reset(
         crypto::SymmetricKey::Import(crypto::SymmetricKey::AES, aes_key));
     encryptor_.reset(new crypto::Encryptor());
     encryptor_->Init(key_.get(), crypto::Encryptor::CTR, std::string());
     is_activated_ = true;
   } else if (aes_iv_mask.size() != 0 || aes_key.size() != 0) {
     DCHECK_EQ(aes_iv_mask.size(), 0u)
@@ skipping 33 matching lines @@
   }
   if (!encryptor_->Decrypt(ciphertext, plaintext)) {
     VLOG(1) << "Decryption error";
     return false;
   }
   return true;
 }
 
 }  // namespace cast
 }  // namespace media