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

chrome/common/pref_names_util_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/common/pref_names_util.h"
 
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace {
 
@@ skipping 10 matching lines @@
 
   ASSERT_TRUE(pref_names_util::ParseFontNamePrefPath(path, &generic_family,
                                                      &script));
   EXPECT_EQ(expected_generic_family, generic_family);
   EXPECT_EQ(expected_script, script);
 }
 
 }  // namespace
 
 TEST(PrefNamesUtilTest, Basic) {
-  ExpectNoParse("");
+  ExpectNoParse(std::string());
   ExpectNoParse(".");
   ExpectNoParse(".....");
   ExpectNoParse("webkit.webprefs.fonts.");
   ExpectNoParse("webkit.webprefs.fonts..");
   ExpectNoParse("webkit.webprefs.fontsfoobar.standard.Hrkt");
   ExpectNoParse("foobar.webprefs.fonts.standard.Hrkt");
   ExpectParse("webkit.webprefs.fonts.standard.Hrkt", "standard", "Hrkt");
   ExpectParse("webkit.webprefs.fonts.standard.Hrkt.", "standard", "Hrkt.");
   ExpectParse("webkit.webprefs.fonts.standard.Hrkt.Foobar", "standard",
               "Hrkt.Foobar");
 
   // We don't particularly care about the parsed family and script for these
   // inputs, but just want to make sure it does something reasonable. Returning
   // false may also be an option.
-  ExpectParse("webkit.webprefs.fonts...", "", ".");
-  ExpectParse("webkit.webprefs.fonts....", "", "..");
+  ExpectParse("webkit.webprefs.fonts...", std::string(), ".");
+  ExpectParse("webkit.webprefs.fonts....", std::string(), "..");
 
   // Check that passing NULL output params is okay.
   EXPECT_TRUE(pref_names_util::ParseFontNamePrefPath(
       "webkit.webprefs.fonts.standard.Hrkt", NULL, NULL));
 }