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

remoting/host/host_change_notification_listener_unittest.cc

Index: remoting/host/host_change_notification_listener_unittest.cc
diff --git a/remoting/host/host_change_notification_listener_unittest.cc b/remoting/host/host_change_notification_listener_unittest.cc
index 1f9305eb2c917a9133d48a19e0282e2b2a256225..5ec6ff8a40e46d6629bcd4ea6167a5d0973e30e1 100644
--- a/remoting/host/host_change_notification_listener_unittest.cc
+++ b/remoting/host/host_change_notification_listener_unittest.cc
@@ -69,9 +69,9 @@ class HostChangeNotificationListenerTest : public testing::Test {
                                                std::string hostId,
                                                std::string botJid) {
     scoped_ptr<XmlElement> stanza(new XmlElement(buzz::QN_IQ));
-    stanza->AddAttr(QName("", "type"), "set");
-    XmlElement* host_changed = new XmlElement(
-        QName(kChromotingXmlNamespace, "host-changed"));
+    stanza->AddAttr(QName(std::string(), "type"), "set");
+    XmlElement* host_changed =
+        new XmlElement(QName(kChromotingXmlNamespace, "host-changed"));
     host_changed->AddAttr(QName(kChromotingXmlNamespace, "operation"),
                           operation);
     host_changed->AddAttr(QName(kChromotingXmlNamespace, "hostid"), hostId);