drive: Add showroot=true to WAPI feed URLs and ignore "no parent" entries.

chrome/browser/chromeos/drive/drive_resource_metadata.cc

Index: chrome/browser/chromeos/drive/drive_resource_metadata.cc
diff --git a/chrome/browser/chromeos/drive/drive_resource_metadata.cc b/chrome/browser/chromeos/drive/drive_resource_metadata.cc
index fbdf510949d941d281a1cc3c5efcba1c1e1a24b5..dc1d7a809314855754c0357b492f102d59cebf61 100644
--- a/chrome/browser/chromeos/drive/drive_resource_metadata.cc
+++ b/chrome/browser/chromeos/drive/drive_resource_metadata.cc
@@ -515,14 +515,17 @@ void DriveResourceMetadata::RefreshEntry(
 
   DriveEntry* old_entry = GetEntryByResourceId(drive_entry->resource_id());
   DriveDirectory* old_parent = NULL;
+  DriveDirectory* new_parent = NULL;
   if (old_entry && !old_entry->parent_resource_id().empty()) {

[hashimoto, 2013/03/11 09:32:17]

Can't this parent_resource_id().empty() check be replaced with old_entry !=
root_.get()?

[Haruki Sato, 2013/03/11 14:15:35]

Yes, assuming all non-root entry has parent_resource_id.
Revised.

     old_parent = GetEntryByResourceId(
         old_entry->parent_resource_id())->AsDriveDirectory();
+    new_parent = entry_proto.parent_resource_id().empty() ? NULL :
+        GetParent(entry_proto.parent_resource_id());

[hashimoto, 2013/03/11 09:32:17]

Why do you allow entry_proto.parent_resource_id() to be empty here?
How about checking it in the if-statement above?

[Haruki Sato, 2013/03/11 14:15:35]

Done. And we can simplify it. Thanks.

   }
-  DriveDirectory* new_parent = GetParent(entry_proto.parent_resource_id());
 
   scoped_ptr<DriveEntryProto> result_entry_proto(new DriveEntryProto);
   // We special case root here because old_parent of root is null.
+  // Note that this also catches "old_entry == NULL" case.
   if ((!old_parent || !new_parent) && old_entry != root_.get()) {
     drive_entry->ToProtoFull(result_entry_proto.get());
     base::MessageLoopProxy::current()->PostTask(
@@ -624,9 +627,7 @@ void DriveResourceMetadata::AddEntry(const DriveEntryProto& entry_proto,
 DriveDirectory* DriveResourceMetadata::GetParent(

[hashimoto, 2013/03/11 09:32:17]

Could you rename this method to GetDirectory() while you are here?
I think the name "GetParent" is quite confusing.

[Haruki Sato, 2013/03/11 14:15:35]

Done.

     const std::string& parent_resource_id) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-
-  if (parent_resource_id.empty())
-    return root_.get();
+  DCHECK(!parent_resource_id.empty());
 
   DriveEntry* entry = GetEntryByResourceId(parent_resource_id);
   return entry ? entry->AsDriveDirectory() : NULL;