Update Commit and GetUpdatesResponse messages to include attachment ids.

sync/internal_api/syncapi_internal.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 "sync/internal_api/syncapi_internal.h"
 
 #include "base/memory/scoped_ptr.h"
+#include "sync/protocol/attachments.pb.h"
 #include "sync/protocol/password_specifics.pb.h"
 #include "sync/protocol/sync.pb.h"
 #include "sync/util/cryptographer.h"
 
 namespace syncer {
 
 namespace {
 
 bool EndsWithSpace(const std::string& string) {
   return !string.empty() && *string.rbegin() == ' ';
@@ skipping 79 matching lines @@
     right_plaintext = cryptographer->DecryptToString(right.encrypted());
   } else {
     right_plaintext = right.SerializeAsString();
   }
   if (left_plaintext == right_plaintext) {
     return true;
   }
   return false;
 }
 
+bool AreAttachmentMetadataEqual(const sync_pb::AttachmentMetadata& left,
+                                const sync_pb::AttachmentMetadata& right) {
+  if (left.SerializeAsString() == right.SerializeAsString()) {
+    return true;
+  }
+  return false;
+}
+
 }  // namespace syncer