Remove chromeos::GDataFileSystem::ParseGDataFeed which lacks method body

chrome/browser/chromeos/gdata/gdata_file_system.h

Index: chrome/browser/chromeos/gdata/gdata_file_system.h
diff --git a/chrome/browser/chromeos/gdata/gdata_file_system.h b/chrome/browser/chromeos/gdata/gdata_file_system.h
index 5ad5996c43f8cdb9da9156ab5633a0091de7e207..cbd177926b6221c34e3bee509d0afbdd652fea83 100644
--- a/chrome/browser/chromeos/gdata/gdata_file_system.h
+++ b/chrome/browser/chromeos/gdata/gdata_file_system.h
@@ -640,12 +640,6 @@ class GDataFileSystem : public GDataFileSystemInterface,
   // Returns NULL if it does not find the entry.
   GDataEntry* GetGDataEntryByPath(const FilePath& file_path);
 
-  // Converts document feed from gdata service into DirectoryInfo. On failure,
-  // returns NULL and fills in |error| with an appropriate value.
-  GDataDirectory* ParseGDataFeed(GDataErrorCode status,
-                                 base::Value* data,
-                                 base::PlatformFileError *error);
-
   // Callback passed to |LoadFeedFromServer| from |SearchAsync| method.
   // |callback| is that should be run with data received from
   // |LoadFeedFromServer|.