Set root resource ID upon full feed update.

chrome/browser/chromeos/drive/drive_feed_processor.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 <utility>
 
 #include "base/metrics/histogram.h"
 #include "chrome/browser/chromeos/drive/drive_feed_processor.h"
 #include "chrome/browser/chromeos/drive/drive_files.h"
 #include "chrome/browser/chromeos/drive/drive_resource_metadata.h"
@@ skipping 71 matching lines @@
   DCHECK(changed_dirs);
 
   if (!is_delta_feed) {  // Full update.
     resource_metadata_->root()->RemoveChildren();
     changed_dirs->insert(resource_metadata_->root()->GetFilePath());
   }
   resource_metadata_->set_largest_changestamp(feed_changestamp);
 
   scoped_ptr<DriveResourceMetadata> orphaned_resources(
       new DriveResourceMetadata);
+  orphaned_resources->InitializeRootEntry("orphanedroot");
   // Go through all entries generated by the feed and apply them to the local
   // snapshot of the file system.
   for (FileResourceIdMap::iterator it = file_map->begin();
        it != file_map->end();) {
     // Ensure that the entry is deleted, unless the ownership is explicitly
     // transferred by entry.release().
     scoped_ptr<DriveEntry> entry(it->second);
     DCHECK_EQ(it->first, entry->resource_id());
     // Erase the entry so the deleted entry won't be referenced.
     file_map->erase(it++);
@@ skipping 192 matching lines @@
     // If the code above fails to parse a feed, any DriveEntry instance
     // added to |file_by_url| is not managed by a DriveDirectory instance,
     // so we need to explicitly release them here.
     STLDeleteValues(file_map);
   }
 
   return error;
 }
 
 }  // namespace drive