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

sync/internal_api/public/base/model_type_invalidation_map_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 "sync/internal_api/public/base/model_type_invalidation_map.h"
 
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
 #include "base/test/values_test_util.h"
@@ skipping 17 matching lines @@
 }
 
 TEST_F(ModelTypeInvalidationMapTest, TypeInvalidationMapToValue) {
   ModelTypeInvalidationMap states;
   states[BOOKMARKS].payload = "bookmarkpayload";
   states[APPS].payload = "";
 
   scoped_ptr<DictionaryValue> value(ModelTypeInvalidationMapToValue(states));
   EXPECT_EQ(2u, value->size());
   ExpectDictStringValue(states[BOOKMARKS].payload, *value, "Bookmarks");
-  ExpectDictStringValue("", *value, "Apps");
+  ExpectDictStringValue(std::string(), *value, "Apps");
   EXPECT_FALSE(value->HasKey("Preferences"));
 }
 
 TEST_F(ModelTypeInvalidationMapTest, CoalesceStates) {
   ModelTypeInvalidationMap original;
   std::string empty_payload;
   std::string payload1 = "payload1";
   std::string payload2 = "payload2";
   std::string payload3 = "payload3";
   original[BOOKMARKS].payload = empty_payload;
@@ skipping 12 matching lines @@
   ASSERT_EQ(5U, original.size());
   EXPECT_EQ(empty_payload, original[BOOKMARKS].payload);
   EXPECT_EQ(payload1, original[PASSWORDS].payload);
   EXPECT_EQ(payload1, original[AUTOFILL].payload);
   EXPECT_EQ(payload2, original[SESSIONS].payload);
   EXPECT_EQ(payload3, original[THEMES].payload);
 }
 
 }  // namespace
 }  // namespace syncer