Quickly close tabs/window with long-running unload handlers.

content/browser/web_contents/web_contents_impl.h

Index: content/browser/web_contents/web_contents_impl.h
diff --git a/content/browser/web_contents/web_contents_impl.h b/content/browser/web_contents/web_contents_impl.h
index 0540ec5be2ebaf2a999752b2fa9073612ed6bd6c..ea8cbfb838312ad31e972c8464188dd5c0637f2c 100644
--- a/content/browser/web_contents/web_contents_impl.h
+++ b/content/browser/web_contents/web_contents_impl.h
@@ -267,6 +267,9 @@ class CONTENT_EXPORT WebContentsImpl
   virtual base::TimeTicks GetNewTabStartTime() const OVERRIDE;
   virtual void Close() OVERRIDE;
   virtual void OnCloseStarted() OVERRIDE;
+  virtual void OnCloseCanceled() OVERRIDE;
+  virtual void OnUnloadStarted() OVERRIDE;
+  virtual void OnUnloadDetachedStarted() OVERRIDE;
   virtual void SystemDragEnded() OVERRIDE;
   virtual void UserGestureDone() OVERRIDE;
   virtual void SetClosedByUserGesture(bool value) OVERRIDE;
@@ -875,6 +878,9 @@ class CONTENT_EXPORT WebContentsImpl
   // The time when onbeforeunload ended.
   base::TimeTicks before_unload_end_time_;
 
+  // The time when the tab was removed from view during close.
+  base::TimeTicks unload_detached_start_time_;
+
   // The time that this tab was last selected.
   base::TimeTicks last_selected_time_;