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

content/browser/download/base_file.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 "content/browser/download/base_file.h"
 
 #include "base/bind.h"
 #include "base/file_util.h"
 #include "base/format_macros.h"
 #include "base/logging.h"
@@ skipping 214 matching lines @@
 
 bool BaseFile::GetHash(std::string* hash) {
   DCHECK(!detached_);
   hash->assign(reinterpret_cast<const char*>(sha256_hash_),
                sizeof(sha256_hash_));
   return (calculate_hash_ && !in_progress());
 }
 
 std::string BaseFile::GetHashState() {
   if (!calculate_hash_)
-    return "";
+    return std::string();
 
   Pickle hash_state;
   if (!secure_hash_->Serialize(&hash_state))
-    return "";
+    return std::string();
 
   return std::string(reinterpret_cast<const char*>(hash_state.data()),
                      hash_state.size());
 }
 
 // static
 bool BaseFile::IsEmptyHash(const std::string& hash) {
   return (hash.size() == kSha256HashLen &&
           0 == memcmp(hash.data(), kEmptySha256Hash, sizeof(kSha256HashLen)));
 }
@@ skipping 119 matching lines @@
     const char* operation,
     int os_error,
     DownloadInterruptReason reason) {
   bound_net_log_.AddEvent(
       net::NetLog::TYPE_DOWNLOAD_FILE_ERROR,
       base::Bind(&FileInterruptedNetLogCallback, operation, os_error, reason));
   return reason;
 }
 
 }  // namespace content