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

chrome/browser/webdata/keyword_table.cc

Index: chrome/browser/webdata/keyword_table.cc
diff --git a/chrome/browser/webdata/keyword_table.cc b/chrome/browser/webdata/keyword_table.cc
index 956d60b9286fc81b668497a5ffd25e88f0d6fada..10d224e8d7431a86be693729c262ac14451095bc 100644
--- a/chrome/browser/webdata/keyword_table.cc
+++ b/chrome/browser/webdata/keyword_table.cc
@@ -388,7 +388,7 @@ bool KeywordTable::MigrateToVersion45RemoveLogoIDAndAutogenerateColumns() {
   // Migrate the keywords backup table as well.
   if (!MigrateKeywordsTableForVersion45("keywords_backup") ||
       !meta_table_->SetValue("Default Search Provider ID Backup Signature",
-                             ""))
+                             std::string()))
     return false;
 
   return transaction.Commit();
@@ -409,7 +409,7 @@ bool KeywordTable::MigrateToVersion47AddAlternateURLsColumn() {
   if (!db_->Execute("ALTER TABLE keywords_backup ADD COLUMN "
                     "alternate_urls VARCHAR DEFAULT ''") ||
       !meta_table_->SetValue("Default Search Provider ID Backup Signature",
-                             ""))
+                             std::string()))
     return false;
 
   return transaction.Commit();