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

crypto/ec_signature_creator_unittest.cc

Index: crypto/ec_signature_creator_unittest.cc
diff --git a/crypto/ec_signature_creator_unittest.cc b/crypto/ec_signature_creator_unittest.cc
index df73bec86db572deaec0b141ced2c7c603e172b5..b34022b1861ec89e39b98870a600652af8ded17b 100644
--- a/crypto/ec_signature_creator_unittest.cc
+++ b/crypto/ec_signature_creator_unittest.cc
@@ -30,13 +30,14 @@ TEST(ECSignatureCreatorTest, BasicTest) {
   ASSERT_TRUE(key_original.get());
 
   std::vector<uint8> key_info;
-  ASSERT_TRUE(key_original->ExportEncryptedPrivateKey("", 1000, &key_info));
+  ASSERT_TRUE(
+      key_original->ExportEncryptedPrivateKey(std::string(), 1000, &key_info));
   std::vector<uint8> pubkey_info;
   ASSERT_TRUE(key_original->ExportPublicKey(&pubkey_info));
 
   scoped_ptr<crypto::ECPrivateKey> key(
-      crypto::ECPrivateKey::CreateFromEncryptedPrivateKeyInfo("", key_info,
-                                                              pubkey_info));
+      crypto::ECPrivateKey::CreateFromEncryptedPrivateKeyInfo(
+          std::string(), key_info, pubkey_info));
   ASSERT_TRUE(key.get());
   ASSERT_TRUE(key->key() != NULL);