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

chrome/browser/profiles/gaia_info_update_service_unittest.cc

Index: chrome/browser/profiles/gaia_info_update_service_unittest.cc
diff --git a/chrome/browser/profiles/gaia_info_update_service_unittest.cc b/chrome/browser/profiles/gaia_info_update_service_unittest.cc
index dd85970911266755071caea88ec7ccd3e05d300f..37dfdd72eddb38d3f04cb49114051de1fa9653e1 100644
--- a/chrome/browser/profiles/gaia_info_update_service_unittest.cc
+++ b/chrome/browser/profiles/gaia_info_update_service_unittest.cc
@@ -184,7 +184,8 @@ TEST_F(GAIAInfoUpdateServiceTest, LogOut) {
   GAIAInfoUpdateService service(profile());
   EXPECT_FALSE(service.GetCachedPictureURL().empty());
   // Log out.
-  profile()->GetPrefs()->SetString(prefs::kGoogleServicesUsername, "");
+  profile()->GetPrefs()
+      ->SetString(prefs::kGoogleServicesUsername, std::string());
 
   // Verify that the GAIA name and picture, and picture URL are unset.
   EXPECT_TRUE(GetCache()->GetGAIANameOfProfileAtIndex(0).empty());
@@ -193,7 +194,8 @@ TEST_F(GAIAInfoUpdateServiceTest, LogOut) {
 }
 
 TEST_F(GAIAInfoUpdateServiceTest, LogIn) {
-  profile()->GetPrefs()->SetString(prefs::kGoogleServicesUsername, "");
+  profile()->GetPrefs()
+      ->SetString(prefs::kGoogleServicesUsername, std::string());
   GAIAInfoUpdateServiceMock service(profile());
 
   // Log in.