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

chrome/browser/internal_auth_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 "chrome/browser/internal_auth.h"
 
 #include <algorithm>
 
 #include "base/lazy_instance.h"
 #include "base/message_loop.h"
@@ skipping 51 matching lines @@
   std::map<std::string, std::string> map;
   map["key"] = "value";
   // Trying huge domain.
   std::string token = InternalAuthGeneration::GeneratePassport(
       long_string_, map);
   ASSERT_TRUE(token.empty());
   ASSERT_FALSE(InternalAuthVerification::VerifyPassport(
       token, long_string_, map));
 
   // Trying empty domain.
-  token = InternalAuthGeneration::GeneratePassport("", map);
+  token = InternalAuthGeneration::GeneratePassport(std::string(), map);
   ASSERT_TRUE(token.empty());
-  ASSERT_FALSE(InternalAuthVerification::VerifyPassport(token, "", map));
+  ASSERT_FALSE(
+      InternalAuthVerification::VerifyPassport(token, std::string(), map));
 
   std::string dummy("abcdefghij");
   for (size_t i = 1000; i--;) {
     std::string key = dummy;
     std::next_permutation(dummy.begin(), dummy.end());
     std::string value = dummy;
     std::next_permutation(dummy.begin(), dummy.end());
     map[key] = value;
   }
   // Trying huge var=value map.
   token = InternalAuthGeneration::GeneratePassport("zapata", map);
   ASSERT_TRUE(token.empty());
   ASSERT_FALSE(InternalAuthVerification::VerifyPassport(token, "zapata", map));
 
   map.clear();
-  map[""] = "value";
+  map[std::string()] = "value";
   // Trying empty key.
   token = InternalAuthGeneration::GeneratePassport("zapata", map);
   ASSERT_TRUE(token.empty());
   ASSERT_FALSE(InternalAuthVerification::VerifyPassport(token, "zapata", map));
 }
 
 TEST_F(InternalAuthTest, BasicVerification) {
   std::map<std::string, std::string> map;
   map["key"] = "value";
   std::string token = InternalAuthGeneration::GeneratePassport("zapata", map);
@@ skipping 77 matching lines @@
 
   token = InternalAuthGeneration::GeneratePassport("zapata", map);
   ASSERT_GT(token.size(), 10u);
   for (int i = 20; i--;)
     InternalAuthGeneration::GenerateNewKey();
   // Passport should not survive series of key changes.
   ASSERT_FALSE(InternalAuthVerification::VerifyPassport(token, "zapata", map));
 }
 
 }  // namespace chrome