Cleanup: Pass std::string as const reference if possible

net/dns/mdns_client_impl.h

 // Copyright 2013 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.
 
 #ifndef NET_DNS_MDNS_CLIENT_IMPL_H_
 #define NET_DNS_MDNS_CLIENT_IMPL_H_
 
 #include <map>
 #include <queue>
 #include <string>
@@ skipping 104 matching lines @@
   // invalidate the core.
   class Core : public base::SupportsWeakPtr<Core>, MDnsConnection::Delegate {
    public:
     Core(base::Clock* clock, base::Timer* timer);
     ~Core() override;
 
     // Initialize the core. Returns true on success.
     bool Init(MDnsSocketFactory* socket_factory);
 
     // Send a query with a specific rrtype and name. Returns true on success.
-    bool SendQuery(uint16 rrtype, std::string name);
+    bool SendQuery(uint16 rrtype, const std::string& name);
 
     // Add/remove a listener to the list of listeners.
     void AddListener(MDnsListenerImpl* listener);
     void RemoveListener(MDnsListenerImpl* listener);
 
     // Query the cache for records of a specific type and name.
     void QueryCache(uint16 rrtype, const std::string& name,
                     std::vector<const RecordParsed*>* records) const;
 
     // Parse the response and alert relevant listeners.
@@ skipping 182 matching lines @@
   MDnsClientImpl* client_;
 
   bool started_;
   int flags_;
 
   DISALLOW_COPY_AND_ASSIGN(MDnsTransactionImpl);
 };
 
 }  // namespace net
 #endif  // NET_DNS_MDNS_CLIENT_IMPL_H_