[Sync] Replace AttachmentIdSet with AttachmentIdList in interfaces.

sync/syncable/directory.cc

 // Copyright 2013 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/syncable/directory.h"
 
 #include <algorithm>
 #include <iterator>
 
 #include "base/base64.h"
@@ skipping 1480 matching lines @@
   }
 }
 
 void Directory::UnmarkDirtyEntry(WriteTransaction* trans, Entry* entry) {
   CHECK(trans);
   entry->kernel_->clear_dirty(&kernel_->dirty_metahandles);
 }
 
 void Directory::GetAttachmentIdsToUpload(BaseTransaction* trans,
                                          ModelType type,
-                                         AttachmentIdSet* id_set) {
+                                         AttachmentIdList* ids) {
   // TODO(maniscalco): Maintain an index by ModelType and rewrite this method to
   // use it.  The approach below is likely very expensive because it iterates
   // all entries (bug 415199).
   DCHECK(trans);
-  DCHECK(id_set);
-  id_set->clear();
+  DCHECK(ids);
+  ids->clear();
   AttachmentIdSet on_server_id_set;
   AttachmentIdSet not_on_server_id_set;
   std::vector<int64> metahandles;
   {
     ScopedKernelLock lock(this);
     GetMetaHandlesOfType(lock, trans, type, &metahandles);
     std::vector<int64>::const_iterator iter = metahandles.begin();
     const std::vector<int64>::const_iterator end = metahandles.end();
     // For all of this type's entries...
     for (; iter != end; ++iter) {
@@ skipping 18 matching lines @@
   }
   // Why did we bother keeping a set of ids known to be on the server?  The
   // is_on_server flag is stored denormalized so we can end up with two entries
   // with the same attachment id where one says it's on the server and the other
   // says it's not.  When this happens, we trust the one that says it's on the
   // server.  To avoid re-uploading the same attachment mulitple times, we
   // remove any ids known to be on the server from the id_set we are about to
   // return.
   //
   // TODO(maniscalco): Eliminate redundant metadata storage (bug 415203).
-  std::set_difference(not_on_server_id_set.begin(),
-                      not_on_server_id_set.end(),
-                      on_server_id_set.begin(),
-                      on_server_id_set.end(),
-                      std::inserter(*id_set, id_set->end()));
+  std::set_difference(not_on_server_id_set.begin(), not_on_server_id_set.end(),
+                      on_server_id_set.begin(), on_server_id_set.end(),
+                      std::back_inserter(*ids));
 }
 
 }  // namespace syncable
 }  // namespace syncer