Allow dragging a download only after the download is complete.

chrome/browser/download/download_util.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.
 //
 // Download utility implementation
 
 #define _USE_MATH_DEFINES  // For VC++ to get M_PI. This has to be first.
 
 #include "chrome/browser/download/download_util.h"
 
@@ skipping 330 matching lines @@
 int GetBigProgressIconOffset() {
   return (GetBigProgressIconSize() - kBigIconSize) / 2;
 }
 
 #if defined(TOOLKIT_VIEWS)
 // Download dragging
 void DragDownload(const DownloadItem* download,
                   gfx::Image* icon,
                   gfx::NativeView view) {
   DCHECK(download);
+  DCHECK(download->IsComplete());
 
   // Set up our OLE machinery
   ui::OSExchangeData data;
 
   if (icon) {
     drag_utils::CreateDragImageForFile(
         download->GetFileNameToReportUser(), icon->ToImageSkia(), &data);
   }
 
-  const FilePath full_path = download->GetFullPath();
+  const FilePath full_path = download->GetTargetFilePath();
   data.SetFilename(full_path);
 
   std::string mime_type = download->GetMimeType();
   if (mime_type.empty())
     net::GetMimeTypeFromFile(full_path, &mime_type);
 
   // Add URL so that we can load supported files when dragged to WebContents.
   if (net::IsSupportedMimeType(mime_type)) {
     data.SetURL(net::FilePathToFileURL(full_path),
                 download->GetFileNameToReportUser().LossyDisplayName());
@@ skipping 123 matching lines @@
   UMA_HISTOGRAM_ENUMERATION(
       "Download.CountsChrome", type, CHROME_DOWNLOAD_COUNT_TYPES_LAST_ENTRY);
 }
 
 void RecordDownloadSource(ChromeDownloadSource source) {
   UMA_HISTOGRAM_ENUMERATION(
       "Download.SourcesChrome", source, CHROME_DOWNLOAD_SOURCE_LAST_ENTRY);
 }
 
 }  // namespace download_util