Implement polling part of DriveFileSyncService

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>
 #include <string>
 #include <vector>
 
 #include "base/callback_forward.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
 #include "base/threading/non_thread_safe.h"
+#include "base/timer.h"
 #include "chrome/browser/google_apis/drive_service_interface.h"
 #include "chrome/browser/google_apis/gdata_wapi_parser.h"
 #include "chrome/browser/sync_file_system/local_change_processor.h"
 #include "chrome/browser/sync_file_system/remote_file_sync_service.h"
 #include "webkit/fileapi/syncable/file_change.h"
 #include "webkit/fileapi/syncable/sync_callbacks.h"
 #include "webkit/fileapi/syncable/sync_operation_type.h"
 
 namespace google_apis {
 class DocumentFeed;
@@ skipping 241 matching lines @@
       scoped_ptr<ProcessRemoteChangeParam> param,
       fileapi::SyncStatusCode status);
   void AbortRemoteSync(
       scoped_ptr<ProcessRemoteChangeParam> param,
       fileapi::SyncStatusCode status);
   void FinalizeRemoteSync(
       scoped_ptr<ProcessRemoteChangeParam> param,
       fileapi::SyncStatusCode status);
 
   void AppendNewRemoteChange(const GURL& origin,
-                             google_apis::DocumentEntry* entry,
+                             const google_apis::DocumentEntry& entry,
                              int64 changestamp,
                              RemoteSyncType sync_type);
   void CancelRemoteChange(const fileapi::FileSystemURL& url);
   void MaybeMarkAsIncrementalSyncOrigin(const GURL& origin);
 
   // This returns false if no change is found for the |url|.
   bool GetPendingChangeForFileSystemURL(const fileapi::FileSystemURL& url,
                                         RemoteChange* change) const;
 
   FilePath temporary_file_dir_;
 
+  void FetchChangesForIncrementalSync();
+  void DidFetchChangesForIncrementalSync(
+      scoped_ptr<TaskToken> token,
+      google_apis::GDataErrorCode error,
+      scoped_ptr<google_apis::DocumentFeed> changes);
+  bool GetOriginForEntry(const google_apis::DocumentEntry& entry, GURL* origin);
+  void SchedulePolling();
+
   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_changestamp_;
+  int64 largest_synced_changestamp_;
+  int64 largest_fetched_changestamp_;
+
   PendingChangeQueue pending_changes_;
   URLToChange url_to_change_;
 
   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_;
+  base::TimeDelta polling_delay_;
+
   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_