Move download filename determintion into a separate class.

chrome/browser/download/download_file_picker.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_DOWNLOAD_DOWNLOAD_FILE_PICKER_H_
 #define CHROME_BROWSER_DOWNLOAD_DOWNLOAD_FILE_PICKER_H_
 
-#include "chrome/browser/download/chrome_download_manager_delegate.h"
+#include "base/callback.h"
 #include "ui/shell_dialogs/select_file_dialog.h"
 
 namespace base {
 class FilePath;
 }
 
 namespace content {
 class DownloadItem;
 class DownloadManager;
 class WebContents;
 }
 
 // Handles showing a dialog to the user to ask for the filename for a download.
 class DownloadFilePicker : public ui::SelectFileDialog::Listener {
  public:
-  DownloadFilePicker();
+  // Callback used to pass the user selection back to the owner of this
+  // object. If the user selection is successful, the arguments will be as
+  // follows:
+  // |virtual_path|: The opaque path representing the virtual target chosen by
+  //     the user. If the target is local file system, then this will be same as
+  //     |local_path|.
+  // |local_path|: The path on the local file system to use for storing the
+  //     downloaded file.
+  //
+  // If the path selection is successful, both paths will be non-empty and
+  // valid. Otherwise, if the user cancels the selection, both paths will be
+  // empty.
+  typedef base::Callback<void(
+      const base::FilePath& virtual_path,
+      const base::FilePath& local_path)> FileSelectedCallback;
+
+  static void ShowFilePicker(content::DownloadItem* item,
+                             const base::FilePath& suggested_path,
+                             const FileSelectedCallback& callback);
+
+ protected:
+  DownloadFilePicker(content::DownloadItem* item,
+                     const base::FilePath& suggested_path,
+                     const FileSelectedCallback& callback);
   virtual ~DownloadFilePicker();
 
-  void Init(content::DownloadManager* download_manager,
-            content::DownloadItem* item,
-            const base::FilePath& suggested_path,
-            const ChromeDownloadManagerDelegate::FileSelectedCallback&
-                callback);
-
- protected:
   // On ChromeOS |suggested_path| might be a temporary local filename. This
   // method should be overridden to set the correct suggested path to prompt the
   // user.
   virtual void InitSuggestedPath(content::DownloadItem* item,
                                  const base::FilePath& suggested_path);
 
   void set_suggested_path(const base::FilePath& suggested_path) {
     suggested_path_ = suggested_path;
   }
 
-  // Runs |file_selected_callback_| with |path| and then deletes this object.
-  void OnFileSelected(const base::FilePath& path);
+  // Runs |file_selected_callback_| with |virtual_path| and |local_path| and
+  // then deletes this object.
+  void OnFileSelected(const base::FilePath& virtual_path,
+                      const base::FilePath& local_path);
 
   void RecordFileSelected(const base::FilePath& path);
 
   scoped_refptr<content::DownloadManager> download_manager_;
   int32 download_id_;
 
  private:
   // SelectFileDialog::Listener implementation.
   virtual void FileSelected(const base::FilePath& path,
                             int index,
                             void* params) OVERRIDE;
   virtual void FileSelectionCanceled(void* params) OVERRIDE;
 
   base::FilePath suggested_path_;
 
-  ChromeDownloadManagerDelegate::FileSelectedCallback file_selected_callback_;
+  FileSelectedCallback file_selected_callback_;
 
   // For managing select file dialogs.
   scoped_refptr<ui::SelectFileDialog> select_file_dialog_;
 
   DISALLOW_COPY_AND_ASSIGN(DownloadFilePicker);
 };
 
 #endif  // CHROME_BROWSER_DOWNLOAD_DOWNLOAD_FILE_PICKER_H_