Fix a crash that happens if a tab is closed while

base/base_drag_source.cc

 // Copyright (c) 2006-2008 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 "base/base_drag_source.h"
 
 ///////////////////////////////////////////////////////////////////////////////
 // BaseDragSource, public:
 
-BaseDragSource::BaseDragSource() : ref_count_(0) {
+BaseDragSource::BaseDragSource() : ref_count_(0), cancel_drag_(false) {
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 // BaseDragSource, IDropSource implementation:
 
 HRESULT BaseDragSource::QueryContinueDrag(BOOL escape_pressed,
                                           DWORD key_state) {
+  if (cancel_drag_)
+    return DRAGDROP_S_CANCEL;
+
   if (escape_pressed) {
     OnDragSourceCancel();
     return DRAGDROP_S_CANCEL;
   }
 
   if (!(key_state & MK_LBUTTON)) {
     OnDragSourceDrop();
     return DRAGDROP_S_DROP;
   }
 
@@ skipping 23 matching lines @@
   return ++ref_count_;
 }
 
 ULONG BaseDragSource::Release() {
   if (--ref_count_ == 0) {
     delete this;
     return 0U;
   }
   return ref_count_;
 }