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

net/dns/single_request_host_resolver_unittest.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 "net/dns/single_request_host_resolver.h"
 
 #include "net/base/address_list.h"
 #include "net/base/net_errors.h"
 #include "net/base/net_log.h"
 #include "net/base/test_completion_callback.h"
@@ skipping 50 matching lines @@
   RequestHandle outstanding_request_;
 
   DISALLOW_COPY_AND_ASSIGN(HangingHostResolver);
 };
 
 // Test that a regular end-to-end lookup returns the expected result.
 TEST(SingleRequestHostResolverTest, NormalResolve) {
   // Create a host resolver dependency that returns address "199.188.1.166"
   // for resolutions of "watsup".
   MockHostResolver resolver;
-  resolver.rules()->AddIPLiteralRule("watsup", "199.188.1.166", "");
+  resolver.rules()->AddIPLiteralRule("watsup", "199.188.1.166", std::string());
 
   SingleRequestHostResolver single_request_resolver(&resolver);
 
   // Resolve "watsup:90" using our SingleRequestHostResolver.
   AddressList addrlist;
   TestCompletionCallback callback;
   HostResolver::RequestInfo request(HostPortPair("watsup", 90));
   int rv = single_request_resolver.Resolve(
       request, &addrlist, callback.callback(), BoundNetLog());
   EXPECT_EQ(ERR_IO_PENDING, rv);
@@ skipping 33 matching lines @@
   SingleRequestHostResolver single_request_resolver(&resolver);
   single_request_resolver.Cancel();
 
   // To pass, HangingHostResolver should not have received a cancellation
   // request (since there is nothing to cancel). If it does, it will crash.
 }
 
 } // namespace
 
 }  // namespace net