Sync FileSystem: Mark empty batch sync origin as incremental sync origin.

chrome/browser/sync_file_system/drive_file_sync_service.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_SYNC_FILE_SYSTEM_DRIVE_FILE_SYNC_SERVICE_H_
 #define CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_FILE_SYNC_SERVICE_H_
 
 #include <deque>
 #include <map>
 #include <set>
@@ skipping 124 matching lines @@
                  PendingChangeQueue::iterator position_in_queue);
     ~RemoteChange();
   };
 
   struct RemoteChangeComparator {
     bool operator()(const RemoteChange& left, const RemoteChange& right);
   };
 
   // TODO(tzik): Consider using std::pair<FilePath, FileType> as the key below
   // to support directories and custom conflict handling.
-  typedef std::map<FilePath, RemoteChange> PathToChange;
-  typedef std::map<GURL, PathToChange> URLToChange;
+  typedef std::map<FilePath, RemoteChange> PathToChangeMap;
+  typedef std::map<GURL, PathToChangeMap> OriginToChangesMap;
 
   // Task types; used for task token handling.
   enum TaskType {
     // No task is holding this token.
     TASK_TYPE_NONE,
 
     // Token is granted for drive-related async task.
     TASK_TYPE_DRIVE,
 
     // Token is granted for async database task.
@@ skipping 182 matching lines @@
   scoped_ptr<DriveMetadataStore> metadata_store_;
   scoped_ptr<DriveFileSyncClient> sync_client_;
 
   fileapi::SyncStatusCode last_operation_status_;
   RemoteServiceState state_;
   std::deque<base::Closure> pending_tasks_;
 
   int64 largest_fetched_changestamp_;
 
   PendingChangeQueue pending_changes_;
-  URLToChange url_to_change_;
+  OriginToChangesMap origin_to_changes_map_;
 
   std::set<GURL> pending_batch_sync_origins_;
 
   // Absence of |token_| implies a task is running. Incoming tasks should
   // wait for the task to finish in |pending_tasks_| if |token_| is null.
   // Each task must take TaskToken instance from |token_| and must hold it
   // until it finished. And the task must return the instance through
   // NotifyTaskDone when the task finished.
   scoped_ptr<TaskToken> token_;
 
   base::OneShotTimer<DriveFileSyncService> polling_timer_;
   int64 polling_delay_seconds_;
   bool polling_enabled_;
 
   ObserverList<Observer> observers_;
 
   // Use WeakPtrFactory instead of SupportsWeakPtr to revoke the weak pointer
   // in |token_|.
   base::WeakPtrFactory<DriveFileSyncService> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DriveFileSyncService);
 };
 
 }  // namespace sync_file_system
 
 #endif  // CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_FILE_SYNC_SERVICE_H_