[SyncFS] Add RemoteToLocalSyncer skeleton

chrome/browser/sync_file_system/drive_backend/remote_to_local_syncer.h

 // Copyright 2013 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_BACKEND_REMOTE_TO_LOCAL_SYNCER_H_
 #define CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_REMOTE_TO_LOCAL_SYNCER_H_
 
+#include "base/memory/weak_ptr.h"
+#include "chrome/browser/sync_file_system/drive_backend/metadata_database.pb.h"
 #include "chrome/browser/sync_file_system/sync_callbacks.h"
 #include "chrome/browser/sync_file_system/sync_task.h"
+#include "chrome/browser/sync_file_system/remote_change_processor.h"
+
+namespace drive {
+class DriveServiceInterface;
+}
 
 namespace sync_file_system {
 namespace drive_backend {
 
+class MetadataDatabase;
+class SyncEngineContext;
+
 class RemoteToLocalSyncer : public SyncTask {
  public:
-  RemoteToLocalSyncer();
+  enum Priority {
+    PRIORITY_NORMAL = 1 << 0,
+    PRIORITY_LOW = 1 << 1,
+  };
+
+  RemoteToLocalSyncer(SyncEngineContext* sync_context,
+                      int priorities);

[kinuko, 2013/11/05 13:36:13]

Please add a comment.

"|priorities| must be a bitwise-or'd value of Priority."

And also add a note about how it changes the syncer's behavior.

[tzik, 2013/11/06 04:56:08]

Done.

   virtual ~RemoteToLocalSyncer();
   virtual void Run(const SyncStatusCallback& callback) OVERRIDE;
 
  private:
+  void ResolveTrivial(const SyncStatusCallback& callback);
+  void DidResolveTrivial(const SyncStatusCallback& callback,
+                         SyncStatusCode status);
+  void DidPrepare(const SyncStatusCallback& callback,
+                  SyncStatusCode status,
+                  const SyncFileMetadata& metadata,
+                  const FileChangeList& changes);
+
+  drive::DriveServiceInterface* drive_service();
+  MetadataDatabase* metadata_database();
+  RemoteChangeProcessor* remote_change_processor();
+  
+  SyncEngineContext* sync_context_;  // Not owned.
+
+  int priorities_;
+  FileTracker dirty_tracker_;
+
+  base::WeakPtrFactory<RemoteToLocalSyncer> weak_ptr_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(RemoteToLocalSyncer);
 };
 
 }  // namespace drive_backend
 }  // namespace sync_file_system
 
 #endif  // CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_REMOTE_TO_LOCAL_SYNCER_H_