Linux: change protobuf default option to allow building

sync/protocol/client_debug_info.proto

 // 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.
 //
 // Common sync protocol for encrypted data.
 
 syntax = "proto2";
 
-option optimize_for = LITE_RUNTIME;
-option retain_unknown_fields = true;
-
 package sync_pb;
 
 import "get_updates_caller_info.proto";
 
 // The additional info here is from the StatusController. They get sent when
 // the event SYNC_CYCLE_COMPLETED  is sent.
 message SyncCycleCompletedEventInfo {
   // optional bool syncer_stuck = 1; // Was always false, now obsolete.
 
   // The client has never set these values correctly.  It set
@@ skipping 62 matching lines @@
   // Whether cryptographer is ready to encrypt and decrypt data.
   optional bool cryptographer_ready = 2;
 
   // Cryptographer has pending keys which indicates the correct passphrase
   // has not been provided yet.
   optional bool cryptographer_has_pending_keys = 3;
 
   // Indicates client has dropped some events to save bandwidth.
   optional bool events_dropped = 4;
 }