Fix 2 drag-out problems:...

chrome/browser/views/tab_contents/tab_contents_drag_win.cc

 // Copyright (c) 2009 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/views/tab_contents/tab_contents_drag_win.h"
 
 #include <windows.h>
 
 #include "base/file_path.h"
 #include "base/message_loop.h"
@@ skipping 266 matching lines @@
     if (!drop_data.file_contents.empty())
       PrepareDragForFileContents(drop_data, &data);
     if (!drop_data.text_html.empty())
       data.SetHtml(drop_data.text_html, drop_data.html_base_url);
     if (drop_data.url.is_valid())
       PrepareDragForUrl(drop_data, &data);
     if (!drop_data.plain_text.empty())
       data.SetString(drop_data.plain_text);
   }
 
+  // Keep a local reference to drag_source_ in case that EndDragging is called
+  // before DoDragDrop returns.
+  scoped_refptr<WebDragSource> drag_source(drag_source_);
+
   // We need to enable recursive tasks on the message loop so we can get
   // updates while in the system DoDragDrop loop.
   bool old_state = MessageLoop::current()->NestableTasksAllowed();
+  MessageLoop::current()->SetNestableTasksAllowed(true);
   DWORD effect;
-  MessageLoop::current()->SetNestableTasksAllowed(true);
   DoDragDrop(OSExchangeDataProviderWin::GetIDataObject(data), drag_source_,
              web_drag_utils_win::WebDragOpToWinDragOp(ops), &effect);
+  MessageLoop::current()->SetNestableTasksAllowed(old_state);
+
   // This works because WebDragSource::OnDragSourceDrop uses PostTask to
   // dispatch the actual event.
-  drag_source_->set_effect(effect);
-  MessageLoop::current()->SetNestableTasksAllowed(old_state);
+  drag_source->set_effect(effect);
 }
 
 void TabContentsDragWin::EndDragging(bool restore_suspended_state) {
   DCHECK(ChromeThread::CurrentlyOn(ChromeThread::UI));
 
   if (drag_ended_)
     return;
   drag_ended_ = true;
 
   if (restore_suspended_state)
@@ skipping 35 matching lines @@
 
 void TabContentsDragWin::OnDataObjectDisposed() {
   DCHECK(drag_drop_thread_id_ == PlatformThread::CurrentId());
 
   // The drag-and-drop thread is only closed after OLE is done with
   // DataObjectImpl.
   ChromeThread::PostTask(
       ChromeThread::UI, FROM_HERE,
       NewRunnableMethod(this, &TabContentsDragWin::CloseThread));
 }