gdata: Make GDataFileSystem::ReadDirectoryByPath() much more efficient

chrome/browser/chromeos/gdata/gdata_download_observer.h

Index: chrome/browser/chromeos/gdata/gdata_download_observer.h
diff --git a/chrome/browser/chromeos/gdata/gdata_download_observer.h b/chrome/browser/chromeos/gdata/gdata_download_observer.h
index 8e13b0e14b2569309d1c1ef83c6a3ed275b8f536..ece654dbc4f075fb9b631b36647ab76e22617c89 100644
--- a/chrome/browser/chromeos/gdata/gdata_download_observer.h
+++ b/chrome/browser/chromeos/gdata/gdata_download_observer.h
@@ -19,7 +19,7 @@ class Profile;
 namespace gdata {
 
 class DocumentEntry;
-class GDataDirectoryProto;
+class GDataEntryProto;
 class GDataFileSystemInterface;
 class GDataUploader;
 struct UploadFileInfo;
@@ -113,16 +113,15 @@ class GDataDownloadObserver : public content::DownloadManager::Observer,
   // Creates UploadFileInfo and initializes it using DownloadItem*.
   void CreateUploadFileInfo(content::DownloadItem* download);
 
-  // Callback for handling results of GDataFileSystem::ReadDirectoryByPath()
+  // Callback for handling results of GDataFileSystem::GetEntryInfoByPath()
   // initiated by CreateUploadFileInfo(). This callback reads the directory
   // entry to determine the upload path, then calls StartUpload() to actually
   // start the upload.
-  void OnReadDirectoryByPath(
+  void OnGetEntryInfoByPath(
       int32 download_id,
       scoped_ptr<UploadFileInfo> upload_file_info,
       GDataFileError error,
-      bool /* hide_hosted_documents */,
-      scoped_ptr<GDataDirectoryProto> dir_proto);
+      scoped_ptr<GDataEntryProto> entry_proto);
 
   // Starts the upload.
   void StartUpload(int32 download_id,