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

sync/internal_api/public/base/ordinal_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 "base/basictypes.h"
 #include "sync/internal_api/public/base/ordinal.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 #include <algorithm>
 #include <cctype>
@@ skipping 69 matching lines @@
                LargeOrdinalkMidDigitValue_incorrect);
 COMPILE_ASSERT(LargeOrdinal::kMaxDigitValue == 255,
                LargeOrdinalkMaxDigitValue_incorrect);
 COMPILE_ASSERT(LargeOrdinal::kRadix == 256,
                LargeOrdinalkRadix_incorrect);
 
 // Create Ordinals that satisfy all but one criterion for validity.
 // IsValid() should return false for all of them.
 TEST(Ordinal, Invalid) {
   // Length criterion.
-  EXPECT_FALSE(TestOrdinal("").IsValid());
+  EXPECT_FALSE(TestOrdinal(std::string()).IsValid());
   EXPECT_FALSE(LongOrdinal("0001").IsValid());
 
   const char kBeforeZero[] = { '0' - 1, '\0' };
   const char kAfterNine[] = { '9' + 1, '\0' };
 
   // Character criterion.
   EXPECT_FALSE(TestOrdinal(kBeforeZero).IsValid());
   EXPECT_FALSE(TestOrdinal("4").IsValid());
   EXPECT_FALSE(LongOrdinal(std::string("0000") + kBeforeZero).IsValid());
   EXPECT_FALSE(LongOrdinal(std::string("0000") + kAfterNine).IsValid());
@@ skipping 266 matching lines @@
   std::vector<LongOrdinal> ordinals = sorted_ordinals;
   std::random_shuffle(ordinals.begin(), ordinals.end());
   std::sort(ordinals.begin(), ordinals.end(), LongOrdinal::LessThanFn());
   EXPECT_TRUE(std::equal(ordinals.begin(), ordinals.end(),
                          sorted_ordinals.begin(), LongOrdinal::EqualsFn()));
 }
 
 }  // namespace
 
 }  // namespace syncer