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

courgette/bsdiff_memory_unittest.cc

 // Copyright (c) 2011 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 "courgette/third_party/bsdiff.h"
 
 #include "courgette/base_test_unittest.h"
 #include "courgette/courgette.h"
 #include "courgette/streams.h"
 
@@ skipping 33 matching lines @@
   std::string result;
   while (result.length() < length) {
     seed = (seed + 17) * 1049 + (seed >> 27);
     result.append(a[seed & 7]);
   }
   result.resize(length);
   return result;
 }
 
 TEST_F(BSDiffMemoryTest, TestEmpty) {
-  GenerateAndTestPatch("", "");
+  GenerateAndTestPatch(std::string(), std::string());
 }
 
 TEST_F(BSDiffMemoryTest, TestEmptyVsNonempty) {
-  GenerateAndTestPatch("", "xxx");
+  GenerateAndTestPatch(std::string(), "xxx");
 }
 
 TEST_F(BSDiffMemoryTest, TestNonemptyVsEmpty) {
-  GenerateAndTestPatch("xxx", "");
+  GenerateAndTestPatch("xxx", std::string());
 }
 
 TEST_F(BSDiffMemoryTest, TestSmallInputsWithSmallChanges) {
   std::string file1 =
       "I would not, could not, in a box.\n"
       "I could not, would not, with a fox.\n"
       "I will not eat them with a mouse.\n"
       "I will not eat them in a house.\n"
       "I will not eat them here or there.\n"
       "I will not eat them anywhere.\n"
@@ skipping 43 matching lines @@
   std::string file1 = FileContents("setup1.exe");
   std::string file2 = FileContents("setup2.exe");
   GenerateAndTestPatch(file1, file2);
 }
 
 TEST_F(BSDiffMemoryTest, TestDifferentElfs) {
   std::string file1 = FileContents("elf-32-1");
   std::string file2 = FileContents("elf-32-2");
   GenerateAndTestPatch(file1, file2);
 }