Fix data overwriting issue on ReadFromDownloadData.

chrome/browser/chromeos/drive/drive_url_request_job.h

Index: chrome/browser/chromeos/drive/drive_url_request_job.h
diff --git a/chrome/browser/chromeos/drive/drive_url_request_job.h b/chrome/browser/chromeos/drive/drive_url_request_job.h
index 7862e77953495b54cef4de72b0ee43475437c28d..ff71fae0ba76a9b81298fd1c6e535abfdda5f5dd 100644
--- a/chrome/browser/chromeos/drive/drive_url_request_job.h
+++ b/chrome/browser/chromeos/drive/drive_url_request_job.h
@@ -11,6 +11,7 @@
 #include "base/callback.h"
 #include "base/files/file_path.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/memory/scoped_vector.h"
 #include "base/memory/weak_ptr.h"
 #include "base/string_piece.h"
 #include "chrome/browser/chromeos/drive/drive_file_error.h"
@@ -131,8 +132,7 @@ class DriveURLRequestJob : public net::URLRequestJob {
   bool streaming_download_;
   scoped_refptr<net::IOBuffer> read_buf_;
   base::StringPiece read_buf_remaining_;
-  std::string download_buf_;
-  base::StringPiece download_buf_remaining_;
+  ScopedVector<std::string> pending_downloaded_data_;
 
   // This should remain the last member so it'll be destroyed first and
   // invalidate its weak pointers before other members are destroyed.