drive: Rewrite UpdateOpreation to access cache/metadata on the blocking pool

chrome/browser/chromeos/drive/file_system/update_operation.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_FILE_SYSTEM_UPDATE_OPERATION_H_
 #define CHROME_BROWSER_CHROMEOS_DRIVE_FILE_SYSTEM_UPDATE_OPERATION_H_
 
 #include "base/basictypes.h"
+#include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
+#include "chrome/browser/chromeos/drive/file_errors.h"
 #include "chrome/browser/chromeos/drive/file_system_interface.h"
 #include "chrome/browser/google_apis/gdata_errorcode.h"
 
 namespace base {
 class FilePath;
+class SequencedTaskRunner;
 }  // namespace base
 
 namespace drive {
 
 class JobScheduler;
 class ResourceEntry;
 
 namespace internal {
 class FileCache;
 class ResourceMetadata;
 }  // namespace internal
 
 namespace file_system {
 
 class OperationObserver;
 
 // This class encapsulates the drive Update function.  It is responsible for
 // sending the request to the drive API, then updating the local state and
 // metadata to reflect the new state.
 class UpdateOperation {
  public:
-  UpdateOperation(OperationObserver* observer,
+  UpdateOperation(base::SequencedTaskRunner* blocking_task_runner,
+                  OperationObserver* observer,
                   JobScheduler* scheduler,
                   internal::ResourceMetadata* metadata,
                   internal::FileCache* cache);
   ~UpdateOperation();
 
   // Updates a file by the given |resource_id| on the Drive server by
   // uploading an updated version. Used for uploading dirty files. The file
   // should already be present in the cache.
   //
   // |callback| must not be null.
   void UpdateFileByResourceId(const std::string& resource_id,
                               DriveClientContext context,
                               const FileOperationCallback& callback);
 
  private:
-  void UpdateFileAfterGetEntryInfo(DriveClientContext context,
-                                   const FileOperationCallback& callback,
-                                   FileError error,
-                                   const base::FilePath& drive_file_path,
-                                   scoped_ptr<ResourceEntry> entry);
-
-  void UpdateFileAfterGetFile(DriveClientContext context,
-                              const FileOperationCallback& callback,
-                              const base::FilePath& drive_file_path,
-                              scoped_ptr<ResourceEntry> entry,
-                              FileError error,
-                              const base::FilePath& cache_file_path);
+  void UpdateFileAfterGetLocalState(DriveClientContext context,
+                                    const FileOperationCallback& callback,
+                                    const ResourceEntry* entry,
+                                    const base::FilePath* drive_file_path,
+                                    const base::FilePath* cache_file_path,
+                                    FileError error);
 
   void UpdateFileAfterUpload(
       const FileOperationCallback& callback,
       google_apis::GDataErrorCode error,
       scoped_ptr<google_apis::ResourceEntry> resource_entry);
 
-  void UpdateFileAfterRefresh(const FileOperationCallback& callback,
-                              FileError error,
-                              const base::FilePath& drive_file_path,
-                              scoped_ptr<ResourceEntry> entry);
+  void UpdateFileAfterUpdateLocalState(const FileOperationCallback& callback,
+                                       const base::FilePath* drive_file_path,
+                                       FileError error);
 
+  scoped_refptr<base::SequencedTaskRunner> blocking_task_runner_;
   OperationObserver* observer_;
   JobScheduler* scheduler_;
   internal::ResourceMetadata* metadata_;
   internal::FileCache* cache_;
 
   // Note: This should remain the last member so it'll be destroyed and
   // invalidate the weak pointers before any other members are destroyed.
   base::WeakPtrFactory<UpdateOperation> weak_ptr_factory_;
   DISALLOW_COPY_AND_ASSIGN(UpdateOperation);
 };
 
 }  // namespace file_system
 }  // namespace drive
 
 #endif  // CHROME_BROWSER_CHROMEOS_DRIVE_FILE_SYSTEM_UPDATE_OPERATION_H_