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

chrome/browser/chromeos/drive/drive_resource_metadata.h

 // 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.
 
 #ifndef CHROME_BROWSER_CHROMEOS_DRIVE_DRIVE_RESOURCE_METADATA_H_
 #define CHROME_BROWSER_CHROMEOS_DRIVE_DRIVE_RESOURCE_METADATA_H_
 
 #include <map>
 #include <set>
 #include <string>
@@ skipping 347 matching lines @@
   void GetEntryInfoPairByPathsAfterGetSecond(
       const base::FilePath& second_path,
       const GetEntryInfoPairCallback& callback,
       scoped_ptr<EntryInfoPairResult> result,
       DriveFileError error,
       scoped_ptr<DriveEntryProto> entry_proto);
 
   // Searches for |file_path| synchronously.
   DriveEntry* FindEntryByPathSync(const base::FilePath& file_path);
 
-  // Helper function to get a parent directory given |parent_resource_id|.
-  // Returns root if |parent_resource_id| is empty. Returns NULL if
-  // |parent_resource_id| is not empty and the corresponding entry is not a
-  // directory.
-  DriveDirectory* GetParent(const std::string& parent_resource_id);
+  // Helper function to get a directory given |resource_id|. |resource_id| can
+  // not be empty. Returns NULL if it finds no corresponding entry, or the
+  // corresponding entry is not a directory.
+  DriveDirectory* GetDirectory(const std::string& resource_id);
 
   // Returns virtual file path of the entry.
   base::FilePath GetFilePath(const DriveEntryProto& entry);
 
   // Recursively extracts the paths set of all sub-directories.
   void GetDescendantDirectoryPaths(const DriveDirectory& directory,
                                    std::set<base::FilePath>* child_directories);
 
   // Private data members.
   scoped_refptr<base::SequencedTaskRunner> blocking_task_runner_;
@@ skipping 12 matching lines @@
   // This should remain the last member so it'll be destroyed first and
   // invalidate its weak pointers before other members are destroyed.
   base::WeakPtrFactory<DriveResourceMetadata> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DriveResourceMetadata);
 };
 
 }  // namespace drive
 
 #endif  // CHROME_BROWSER_CHROMEOS_DRIVE_DRIVE_RESOURCE_METADATA_H_