drive: Simplify DownloadOperation by using ResourceEntry::local_id

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

Index: chrome/browser/chromeos/drive/file_system/download_operation.h
diff --git a/chrome/browser/chromeos/drive/file_system/download_operation.h b/chrome/browser/chromeos/drive/file_system/download_operation.h
index ac1e13ec3b8b75573c80a20b104dbc0fc0db9324..e81a3f2cfead72b836a906eabe64554a0a3c6dd5 100644
--- a/chrome/browser/chromeos/drive/file_system/download_operation.h
+++ b/chrome/browser/chromeos/drive/file_system/download_operation.h
@@ -86,7 +86,6 @@ class DownloadOperation {
   void EnsureFileDownloadedAfterCheckPreCondition(
       scoped_ptr<DownloadParams> params,
       const ClientContext& context,
-      std::string* local_id,
       base::FilePath* drive_file_path,
       base::FilePath* cache_file_path,
       FileError error);
@@ -96,7 +95,6 @@ class DownloadOperation {
   void EnsureFileDownloadedAfterPrepareForDownloadFile(
       scoped_ptr<DownloadParams> params,
       const ClientContext& context,
-      const std::string& local_id,
       const base::FilePath& drive_file_path,
       base::FilePath* temp_download_file_path,
       FileError error);
@@ -104,7 +102,6 @@ class DownloadOperation {
   // Part of EnsureFileDownloaded(). Called after the actual downloading.
   void EnsureFileDownloadedAfterDownloadFile(
       const base::FilePath& drive_file_path,
-      const std::string& local_id,
       scoped_ptr<DownloadParams> params,
       google_apis::GDataErrorCode gdata_error,
       const base::FilePath& downloaded_file_path);