Set root resource ID upon full feed update.

chrome/browser/chromeos/drive/drive_feed_loader.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/drive/drive_feed_loader.h"
 
 #include <set>
 
 #include "base/command_line.h"
 #include "base/file_util.h"
@@ skipping 359 matching lines @@
   scoped_ptr<google_apis::AboutResource> about_resource;
   if (feed_data.get())
     about_resource = google_apis::AboutResource::CreateFrom(*feed_data);
 
   if (!about_resource.get()) {
     LoadFromServer(params.Pass());
     return;
   }
 
   int64 largest_changestamp = about_resource->largest_change_id();
-  resource_metadata_->InitializeRootEntry(about_resource->root_folder_id());
+
+  // Copy the root resource ID for use in UpdateFromFeed().
+  params->root_resource_id = about_resource->root_folder_id();
+  DCHECK(!params->root_resource_id.empty());
 
   if (local_changestamp >= largest_changestamp) {
     if (local_changestamp > largest_changestamp) {
       LOG(WARNING) << "Cached client feed is fresher than server, client = "
                    << local_changestamp
                    << ", server = "
                    << largest_changestamp;
     }
 
     // No changes detected, tell the client that the loading was successful.
@@ skipping 78 matching lines @@
 
 void DriveFeedLoader::OnFeedFromServerLoaded(scoped_ptr<LoadFeedParams> params,
                                              DriveFileError error) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   DCHECK(!params->load_finished_callback.is_null());
   DCHECK(refreshing_);
 
   if (error == DRIVE_FILE_OK) {
     UpdateFromFeed(params->feed_list,
                    params->start_changestamp,
-                   params->root_feed_changestamp);
+                   params->root_feed_changestamp,
+                   params->root_resource_id);
   }
   refreshing_ = false;
 
   if (error != DRIVE_FILE_OK) {
     params->load_finished_callback.Run(error);
     return;
   }
 
   // Save file system metadata to disk.
   SaveFileSystem();
@@ skipping 351 matching lines @@
         FROM_HERE,
         blocking_task_runner_,
         base::Bind(&SaveProtoOnBlockingPool, path,
                    base::Passed(serialized_proto.Pass())));
   }
 }
 
 void DriveFeedLoader::UpdateFromFeed(
     const ScopedVector<google_apis::DocumentFeed>& feed_list,
     int64 start_changestamp,
-    int64 root_feed_changestamp) {
+    int64 root_feed_changestamp,
+    const std::string& root_resource_id) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   DVLOG(1) << "Updating directory with a feed";
 
   std::set<FilePath> changed_dirs;
 
+  if (start_changestamp == 0) {
+    // This is a full fetch and on full fetch the root has to be initialized
+    // before children are added by DriveFeedProcessor.
+    if (google_apis::util::IsDriveV2ApiEnabled()) {
+      DCHECK(!root_resource_id.empty());
+      resource_metadata_->InitializeRootEntry(root_resource_id);
+    } else {
+      // Use fixed root resource ID for WAPI.
+      resource_metadata_->InitializeRootEntry(kWAPIRootDirectoryResourceId);
+    }
+  }
+
   DriveFeedProcessor feed_processor(resource_metadata_);
   feed_processor.ApplyFeeds(
       feed_list,
       start_changestamp,
       root_feed_changestamp,
       &changed_dirs);
 
   // Don't send directory content change notification while performing
   // the initial content retrieval.
   const bool should_notify_directory_changed = (start_changestamp != 0);
   if (should_notify_directory_changed) {
     for (std::set<FilePath>::iterator dir_iter = changed_dirs.begin();
         dir_iter != changed_dirs.end(); ++dir_iter) {
       FOR_EACH_OBSERVER(DriveFeedLoaderObserver, observers_,
                         OnDirectoryChanged(*dir_iter));
     }
   }
 }
 
 }  // namespace drive