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

chrome/browser/password_manager/native_backend_kwallet_x.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 "chrome/browser/password_manager/native_backend_kwallet_x.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/logging.h"
@@ skipping 168 matching lines @@
       session_bus_->GetObjectProxy(kKLauncherServiceName,
                                    dbus::ObjectPath(kKLauncherPath));
 
   dbus::MethodCall method_call(kKLauncherInterface,
                                "start_service_by_desktop_name");
   dbus::MessageWriter builder(&method_call);
   std::vector<std::string> empty;
   builder.AppendString("kwalletd");     // serviceName
   builder.AppendArrayOfStrings(empty);  // urls
   builder.AppendArrayOfStrings(empty);  // envs
-  builder.AppendString("");             // startup_id
+  builder.AppendString(std::string());  // startup_id
   builder.AppendBool(false);            // blind
   scoped_ptr<dbus::Response> response(
       klauncher->CallMethodAndBlock(
           &method_call, dbus::ObjectProxy::TIMEOUT_USE_DEFAULT));
   if (!response.get()) {
     LOG(ERROR) << "Error contacting klauncher to start kwalletd";
     return false;
   }
   dbus::MessageReader reader(response.get());
   int32_t ret = -1;
@@ skipping 761 matching lines @@
     // Each other profile must be able to migrate the shared data as well,
     // so we must leave it alone. After a few releases, we'll add code to
     // delete them, and eventually remove this migration code.
     // TODO(mdm): follow through with the plan above.
     PasswordStoreX::SetPasswordsUseLocalProfileId(prefs_);
   } else {
     // We failed to migrate for some reason. Use the old folder name.
     folder_name_ = kKWalletFolder;
   }
 }