Added callback to DownloadUrl() so we can find download failures.

content/browser/download/drag_download_file.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 "content/browser/download/drag_download_file.h"
 
 #include "base/bind.h"
 #include "base/file_util.h"
 #include "base/message_loop.h"
 #include "content/browser/download/download_stats.h"
@@ skipping 123 matching lines @@
   save_info.file_stream = file_stream_;
 
   download_stats::RecordDownloadSource(
       download_stats::INITIATED_BY_DRAG_N_DROP);
   download_manager_->DownloadUrl(url_,
                                  referrer_,
                                  referrer_encoding_,
                                  false,
                                  -1,
                                  save_info,
-                                 web_contents_);
+                                 web_contents_,
+                                 DownloadManager::OnStartedCallback());
 }
 
 void DragDownloadFile::DownloadCompleted(bool is_successful) {
 #if defined(OS_WIN)
   // If not in drag-and-drop thread, defer the running to it.
   if (drag_message_loop_ != MessageLoop::current()) {
     drag_message_loop_->PostTask(
         FROM_HERE,
         base::Bind(&DragDownloadFile::DownloadCompleted, this, is_successful));
     return;
@@ skipping 76 matching lines @@
 
 void DragDownloadFile::QuitNestedMessageLoop() {
   AssertCurrentlyOnDragThread();
 
   if (is_running_nested_message_loop_) {
     is_running_nested_message_loop_ = false;
     MessageLoop::current()->Quit();
   }
 }
 #endif