Rewrite std::string("") to std::string(), Linux edition.

sync/util/cryptographer.cc

 // Copyright (c) 2012 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 "sync/util/cryptographer.h"
 
 #include <algorithm>
 
 #include "base/base64.h"
 #include "base/basictypes.h"
@@ skipping 92 matching lines @@
   DCHECK(message);
   std::string plaintext = DecryptToString(encrypted);
   return message->ParseFromString(plaintext);
 }
 
 std::string Cryptographer::DecryptToString(
     const sync_pb::EncryptedData& encrypted) const {
   NigoriMap::const_iterator it = nigoris_.find(encrypted.key_name());
   if (nigoris_.end() == it) {
     NOTREACHED() << "Cannot decrypt message";
-    return std::string("");  // Caller should have called CanDecrypt(encrypt).
+    return std::string();  // Caller should have called CanDecrypt(encrypt).
   }
 
   std::string plaintext;
   if (!it->second->Decrypt(encrypted.blob(), &plaintext)) {
-    return std::string("");
+    return std::string();
   }
 
   return plaintext;
 }
 
 bool Cryptographer::GetKeys(sync_pb::EncryptedData* encrypted) const {
   DCHECK(encrypted);
   DCHECK(!nigoris_.empty());
 
   // Create a bag of all the Nigori parameters we know about.
@@ skipping 135 matching lines @@
   if (!base::Base64Encode(encrypted_token, token)) {
     NOTREACHED();
     return false;
   }
   return true;
 }
 
 std::string Cryptographer::UnpackBootstrapToken(
     const std::string& token) const {
   if (token.empty())
-    return "";
+    return std::string();
 
   std::string encrypted_data;
   if (!base::Base64Decode(token, &encrypted_data)) {
     DLOG(WARNING) << "Could not decode token.";
-    return "";
+    return std::string();
   }
 
   std::string unencrypted_token;
   if (!encryptor_->DecryptString(encrypted_data, &unencrypted_token)) {
     DLOG(WARNING) << "Decryption of bootstrap token failed.";
-    return "";
+    return std::string();
   }
   return unencrypted_token;
 }
 
 void Cryptographer::InstallKeyBag(const sync_pb::NigoriKeyBag& bag) {
   int key_size = bag.key_size();
   for (int i = 0; i < key_size; ++i) {
     const sync_pb::NigoriKey key = bag.key(i);
     // Only use this key if we don't already know about it.
     if (nigoris_.end() == nigoris_.find(key.name())) {
@@ skipping 25 matching lines @@
                << "Assuming keybag is corrupted.";
     return true;
   }
   if (static_cast<size_t>(bag.key_size()) < nigoris_.size())
     return true;
   return false;
 }
 
 std::string Cryptographer::GetDefaultNigoriKey() const {
   if (!is_initialized())
-    return "";
+    return std::string();
   NigoriMap::const_iterator iter = nigoris_.find(default_nigori_name_);
   if (iter == nigoris_.end())
-    return "";
+    return std::string();
   sync_pb::NigoriKey key;
   if (!iter->second->ExportKeys(key.mutable_user_key(),
                                 key.mutable_encryption_key(),
                                 key.mutable_mac_key()))
-    return "";
+    return std::string();
   return key.SerializeAsString();
 }
 
 bool Cryptographer::ImportNigoriKey(const std::string serialized_nigori_key) {
   if (serialized_nigori_key.empty())
     return false;
 
   sync_pb::NigoriKey key;
   if (!key.ParseFromString(serialized_nigori_key))
     return false;
 
   scoped_ptr<Nigori> nigori(new Nigori);
   if (!nigori->InitByImport(key.user_key(), key.encryption_key(),
                             key.mac_key())) {
     NOTREACHED();
     return false;
   }
 
   if (!AddKeyImpl(nigori.Pass(), true))
     return false;
   return true;
 }
 
 }  // namespace syncer