Move download filename determintion into a separate class.

chrome/browser/download/download_file_picker_chromeos.h

Index: chrome/browser/download/download_file_picker_chromeos.h
diff --git a/chrome/browser/download/download_file_picker_chromeos.h b/chrome/browser/download/download_file_picker_chromeos.h
index 2d97318fb825099f0448776ca296b18c2e64bf6f..86de15c71f9fcfa1282394d72efc599f00c0625f 100644
--- a/chrome/browser/download/download_file_picker_chromeos.h
+++ b/chrome/browser/download/download_file_picker_chromeos.h
@@ -12,11 +12,10 @@ struct SelectedFileInfo;
 }
 
 class DownloadFilePickerChromeOS : public DownloadFilePicker {
- public:
+ private:
   DownloadFilePickerChromeOS();
   virtual ~DownloadFilePickerChromeOS();
 
- private:
   // SelectFileDialog::Listener implementation.
   virtual void FileSelected(const base::FilePath& path,
                             int index,