Set root resource ID upon full feed update.

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 <string>
 #include <vector>
@@ skipping 41 matching lines @@
   // Content is initialized from disk cache.
   FROM_CACHE,
   // Content is initialized from the direct server response.
   FROM_SERVER,
 };
 
 // The root directory name used for the Google Drive file system tree. The
 // name is used in URLs for the file manager, hence user-visible.
 const FilePath::CharType kDriveRootDirectory[] = FILE_PATH_LITERAL("drive");
 
-// The resource ID for the root directory is defined in the spec:
-// https://developers.google.com/google-apps/documents-list/
-const char kDriveRootDirectoryResourceId[] = "folder:root";
-
 // This should be incremented when incompatibility change is made in
 // drive.proto.
 const int32 kProtoVersion = 2;
 
 // Used for file operations like removing files.
 typedef base::Callback<void(DriveFileError error)>
     FileOperationCallback;
 
 // Callback similar to FileOperationCallback but with a given |file_path|.
 // Used for operations that change a file path like moving files.
@@ skipping 179 matching lines @@
   void SerializeToString(std::string* serialized_proto) const;
   bool ParseFromString(const std::string& serialized_proto);
 
   // Restores from and saves to database, calling |callback| asynchronously.
   // |callback| must not be null.
   void InitFromDB(const FilePath& db_path,
                   base::SequencedTaskRunner* blocking_task_runner,
                   const FileOperationCallback& callback);
   void SaveToDB();
 
+  // Returns the resource ID of the root directory or empty string if it is
+  // not initialized.
+  const std::string& root_resource_id() const;
+
  private:
   // Initializes the resource map using serialized_resources fetched from the
   // database.
   // |callback| must not be null.
   void InitResourceMap(CreateDBParams* create_params,
                        const FileOperationCallback& callback);
 
   // Clears root_ and the resource map.
   void ClearRoot();
 
@@ skipping 25 matching lines @@
   DriveEntry* FindEntryByPathSync(const FilePath& file_path);
 
   // Private data members.
   scoped_refptr<base::SequencedTaskRunner> blocking_task_runner_;
   scoped_ptr<ResourceMetadataDB> resource_metadata_db_;
 
   ResourceMap resource_map_;
 
   scoped_ptr<DriveDirectory> root_;  // Stored in the serialized proto.
 
+  // Retains special resource ID for the root directory across |ClearRoot()|.
+  // This must be initialized only once using |InitializeRootEntry()|.
+  // This value will be used to look up the root direcotry in |InitFromDB()|.
+  std::string saved_root_resource_id_;
+
   base::Time last_serialized_;
   size_t serialized_size_;
   int64 largest_changestamp_;  // Stored in the serialized proto.
   ContentOrigin origin_;
 
   // 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_