Allow dragging a download only after the download is complete.

chrome/browser/chromeos/drive/drive_download_observer.cc

 // 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.
 
 #include "chrome/browser/chromeos/drive/drive_download_observer.h"
 
 #include "base/bind.h"
 #include "base/file_util.h"
 #include "base/supports_user_data.h"
 #include "chrome/browser/chromeos/drive/drive.pb.h"
@@ skipping 233 matching lines @@
     case DownloadItem::INTERRUPTED:
       download->SetUserData(&kDrivePathKey, NULL);
       break;
 
     default:
       NOTREACHED();
   }
 }
 
 void DriveDownloadObserver::UploadDownloadItem(DownloadItem* download) {
+  DCHECK(download->IsComplete());
   file_write_helper_->PrepareWritableFileAndRun(
       GetDrivePath(download),
-      base::Bind(&MoveDownloadedFile, download->GetFullPath()));
+      base::Bind(&MoveDownloadedFile, download->GetTargetFilePath()));
 }
 
 }  // namespace drive