Revert 164876 - Set root resource ID upon full feed update.

chrome/browser/chromeos/drive/drive_feed_loader.cc

Index: chrome/browser/chromeos/drive/drive_feed_loader.cc
===================================================================
--- chrome/browser/chromeos/drive/drive_feed_loader.cc	(revision 164882)
+++ chrome/browser/chromeos/drive/drive_feed_loader.cc	(working copy)
@@ -377,11 +377,8 @@
   }
 
   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 = "
@@ -479,8 +476,7 @@
   if (error == DRIVE_FILE_OK) {
     UpdateFromFeed(params->feed_list,
                    params->start_changestamp,
-                   params->root_feed_changestamp,
-                   params->root_resource_id);
+                   params->root_feed_changestamp);
   }
   refreshing_ = false;
 
@@ -852,25 +848,12 @@
 void DriveFeedLoader::UpdateFromFeed(
     const ScopedVector<google_apis::DocumentFeed>& feed_list,
     int64 start_changestamp,
-    int64 root_feed_changestamp,
-    const std::string& root_resource_id) {
+    int64 root_feed_changestamp) {
   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,