Add drive::FileSystem::GetFileByPathForSaving().

chrome/browser/chromeos/drive/file_system/get_file_for_saving_operation.h

Index: chrome/browser/chromeos/drive/file_system/get_file_for_saving_operation.h
diff --git a/chrome/browser/chromeos/drive/file_system/get_file_for_saving_operation.h b/chrome/browser/chromeos/drive/file_system/get_file_for_saving_operation.h
new file mode 100644
index 0000000000000000000000000000000000000000..3215cc27401b4575e99c97da83942b2412080b05
--- /dev/null
+++ b/chrome/browser/chromeos/drive/file_system/get_file_for_saving_operation.h
@@ -0,0 +1,92 @@
+// 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_CHROMEOS_DRIVE_FILE_SYSTEM_GET_FILE_FOR_SAVING_OPERATION_H_
+#define CHROME_BROWSER_CHROMEOS_DRIVE_FILE_SYSTEM_GET_FILE_FOR_SAVING_OPERATION_H_
+
+#include "base/basictypes.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"
+
+namespace base {
+class FilePath;
+class SequencedTaskRunner;
+}  // namespace base
+
+namespace drive {
+namespace internal {
+class FileCache;
+class FileWriteWatcher;
+class ResourceMetadata;
+}  // namespace internal
+
+class JobScheduler;
+class ResourceEntry;
+
+namespace file_system {
+
+class CreateFileOperation;
+class DownloadOperation;
+class OperationObserver;
+
+// Implements GetFileForSaving() operation that prepares a local cache for
+// a Drive file whose next modification is monitored and notified to the
+// OperationObserver.
+// TODO(kinaba): crbug.com/269424: we might want to monitor all the changes
+// to the cache directory, not just the one immediately after the save dialog.
+class GetFileForSavingOperation {
+ public:
+  GetFileForSavingOperation(base::SequencedTaskRunner* blocking_task_runner,
+                            OperationObserver* observer,
+                            JobScheduler* scheduler,
+                            internal::ResourceMetadata* metadata,
+                            internal::FileCache* cache,
+                            const base::FilePath& temporary_file_directory);
+  ~GetFileForSavingOperation();
+
+  // Makes sure that |file_path| in the file system is available in the local
+  // cache, and marks it as dirty. The next modification to the cache file is
+  // watched and is automatically notified to the observer. If the entry is not
+  // present in the file system, it is created.
+  void GetFileForSaving(const base::FilePath& file_path,
+                        const GetFileCallback& callback);
+
+  internal::FileWriteWatcher* file_write_watcher_for_testing() {
+    return file_write_watcher_.get();
+  }
+
+ private:
+  void GetFileForSavingAfterCreate(const base::FilePath& file_path,
+                                   const GetFileCallback& callback,
+                                   FileError error);
+  void GetFileForSavingAfterDownload(const GetFileCallback& callback,
+                                     FileError error,
+                                     const base::FilePath& cache_path,
+                                     scoped_ptr<ResourceEntry> entry);
+  void GetFileForSavingAfterMarkDirty(const GetFileCallback& callback,
+                                      const base::FilePath& cache_path,
+                                      scoped_ptr<ResourceEntry> entry,
+                                      FileError error);
+  void GetFileForSavingAfterWatch(const GetFileCallback& callback,
+                                  const base::FilePath& cache_path,
+                                  scoped_ptr<ResourceEntry> entry,
+                                  bool success);
+
+  scoped_ptr<CreateFileOperation> create_file_operation_;
+  scoped_ptr<DownloadOperation> download_operation_;
+  scoped_ptr<internal::FileWriteWatcher> file_write_watcher_;
+  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<GetFileForSavingOperation> weak_ptr_factory_;
+  DISALLOW_COPY_AND_ASSIGN(GetFileForSavingOperation);
+};
+
+}  // namespace file_system
+}  // namespace drive
+
+#endif  // CHROME_BROWSER_CHROMEOS_DRIVE_FILE_SYSTEM_GET_FILE_FOR_SAVING_OPERATION_H_