Switched sync protobufs to use "heavy" protobufs.

chrome/browser/sync/protocol/password_specifics.proto

 // Copyright (c) 2010 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.
 //
 // Sync protocol datatype extension for password data.
 
 syntax = "proto2";
 
-option optimize_for = LITE_RUNTIME;
+// TODO(akalin): Re-enable this once LITE_RUNTIME supports preserving
+// unknown fields.
+
+// option optimize_for = LITE_RUNTIME;
 
 package sync_pb;
 
 import "encryption.proto";
 import "sync.proto";
 
 // These are the properties that get serialized into the |encrypted| field of
 // PasswordSpecifics.
 message PasswordSpecificsData {
   optional int32 scheme = 1;
@@ skipping 12 matching lines @@
 
 // Properties of password sync objects. The actual password data is held in a
 // PasswordSpecificsData that is encrypted into |encrypted|.
 message PasswordSpecifics {
   optional EncryptedData encrypted = 1;
 }
 
 extend EntitySpecifics {
   optional PasswordSpecifics password = 45873;
 }