child_files_ and child_directories_ have resource_ids instead of GDataFile* and GDataDirectory*.

chrome/browser/chromeos/gdata/gdata_directory_service.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 "chrome/browser/chromeos/gdata/gdata_directory_service.h"
 
 #include <leveldb/db.h>
 #include <utility>
 
 #include "base/message_loop_proxy.h"
@@ skipping 282 matching lines @@
 GDataEntry* GDataDirectoryService::FindEntryByPathSync(
     const FilePath& file_path) {
   if (file_path == root_->GetFilePath())
     return root_.get();
 
   std::vector<FilePath::StringType> components;
   file_path.GetComponents(&components);
   GDataDirectory* current_dir = root_.get();
 
   for (size_t i = 1; i < components.size() && current_dir; ++i) {
-    GDataEntry* entry = current_dir->FindChild(components[i]);
-    if (!entry)
+    std::string resource_id = current_dir->FindChild(components[i]);
+    if (resource_id.empty())
       return NULL;
 
+    GDataEntry* entry = GetEntryByResourceId(resource_id);
+    DCHECK(entry);
+
     if (i == components.size() - 1)  // Last component.
       return entry;
     else
       current_dir = entry->AsGDataDirectory();
   }
   return NULL;
 }
 
 GDataEntry* GDataDirectoryService::GetEntryByResourceId(
-    const std::string& resource) {
-  // GDataFileSystem has already locked.
-  ResourceMap::const_iterator iter = resource_map_.find(resource);
+    const std::string& resource_id) {
+  DCHECK(!resource_id.empty());
+  ResourceMap::const_iterator iter = resource_map_.find(resource_id);
   return iter == resource_map_.end() ? NULL : iter->second;
 }
 
 void GDataDirectoryService::GetEntryByResourceIdAsync(
     const std::string& resource_id,
     const GetEntryByResourceIdCallback& callback) {
   GDataEntry* entry = GetEntryByResourceId(resource_id);
   callback.Run(entry);
 }
 
@@ skipping 391 matching lines @@
   DCHECK(result.get());
 
   result->second.path = second_path;
   result->second.error = error;
   result->second.proto = entry_proto.Pass();
 
   callback.Run(result.Pass());
 }
 
 }  // namespace gdata