[Mac] Delay TabContents::Close() when event-tracking.

chrome/browser/tab_contents/tab_contents_view.h

 // 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.
 
 #ifndef CHROME_BROWSER_TAB_CONTENTS_TAB_CONTENTS_VIEW_H_
 #define CHROME_BROWSER_TAB_CONTENTS_TAB_CONTENTS_VIEW_H_
 
 #include <map>
 #include <string>
 
@@ skipping 118 matching lines @@
   }
 
   // If we try to close the tab while a drag is in progress, we crash.  These
   // methods allow the tab contents to determine if a drag is in progress and
   // postpone the tab closing.
   virtual bool IsDoingDrag() const {
     return false;
   }
   virtual void CancelDragAndCloseTab() {}
 
+  // If we close the tab while a UI control is in an event-tracking
+  // loop, the control may message freed objects and crash.
+  // TabContents::Close() calls IsEventTracking(), and if it returns
+  // true CloseTabAfterEventTracking() is called and the close is not
+  // completed.
+  virtual bool IsEventTracking() const {
+    return false;
+  }
+  virtual void CloseTabAfterEventTracking() {}
+
  protected:
   TabContentsView() {}  // Abstract interface.
 
   // Internal functions used to support the CreateNewWidget() method. If a
   // platform requires plugging into widget creation at a lower level then a
   // subclass might want to override these functions, but otherwise they should
   // be fine just implementing RenderWidgetHostView::InitAsPopup().
   //
   // The Create function returns the newly created widget so it can be
   // associated with the given route. When the widget needs to be shown later,
@@ skipping 34 matching lines @@
   typedef std::map<int, RenderWidgetHostView*> PendingWidgetViews;
   PendingWidgetViews pending_widget_views_;
 
   // The page content's intrinsic width.
   int preferred_width_;
 
   DISALLOW_COPY_AND_ASSIGN(TabContentsView);
 };
 
 #endif  // CHROME_BROWSER_TAB_CONTENTS_TAB_CONTENTS_VIEW_H_