Make PassphraseType a "enum class" instead of "enum".

components/sync/engine/sync_string_conversions.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 "components/sync/engine/sync_string_conversions.h"
 
 #define ENUM_CASE(x) \
   case x:            \
     return #x
 
@@ skipping 17 matching lines @@
     ENUM_CASE(REASON_ENCRYPTION);
     ENUM_CASE(REASON_DECRYPTION);
     default:
       NOTREACHED();
       return "INVALID_REASON";
   }
 }
 
 const char* PassphraseTypeToString(PassphraseType type) {
   switch (type) {
-    ENUM_CASE(IMPLICIT_PASSPHRASE);
-    ENUM_CASE(KEYSTORE_PASSPHRASE);
-    ENUM_CASE(FROZEN_IMPLICIT_PASSPHRASE);
-    ENUM_CASE(CUSTOM_PASSPHRASE);
+    ENUM_CASE(PassphraseType::IMPLICIT_PASSPHRASE);
+    ENUM_CASE(PassphraseType::KEYSTORE_PASSPHRASE);
+    ENUM_CASE(PassphraseType::FROZEN_IMPLICIT_PASSPHRASE);
+    ENUM_CASE(PassphraseType::CUSTOM_PASSPHRASE);
     default:
       NOTREACHED();
       return "INVALID_PASSPHRASE_TYPE";
   }
 }
 
 const char* BootstrapTokenTypeToString(BootstrapTokenType type) {
   switch (type) {
     ENUM_CASE(PASSPHRASE_BOOTSTRAP_TOKEN);
     ENUM_CASE(KEYSTORE_BOOTSTRAP_TOKEN);
     default:
       NOTREACHED();
       return "INVALID_BOOTSTRAP_TOKEN_TYPE";
   }
 }
 
 }  // namespace syncer