[Sync] Move //sync to //components/sync.

components/sync/protocol/attachments.proto

 // Copyright 2014 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 for attachments.
 
 // Update proto_{value,enum}_conversions{.h,.cc,_unittest.cc} if you change any
 // fields in this file.
 
 syntax = "proto2";
@@ skipping 20 matching lines @@
   // Indicates we know this attachment exists on the server.
   optional bool is_on_server = 2;
 }
 
 // A collection of attachment metadata. This proto is part of EntryKernel's "on
 // disk" representation. Private to sync.
 message AttachmentMetadata {
   // One record per attachment.
   repeated AttachmentMetadataRecord record = 1;
 }