Inform the WebFrameClient of BeforeUnload/Unload handlers

public/platform/Platform.h

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 379 matching lines @@
 
 
     // Scrollbar ----------------------------------------------------------
 
     // Must return non-null.
     virtual WebScrollbarBehavior* scrollbarBehavior() { return 0; }
 
 
     // Sudden Termination --------------------------------------------------
 
-    // Disable/Enable sudden termination.
+    // Disable/Enable sudden termination on a process level. When possible, it
+    // is preferable to disable sudden termination on a per-frame level via
+    // WebFrameClient::suddenTerminationDisablerChanged.
     virtual void suddenTerminationChanged(bool enabled) { }
 
 
     // System --------------------------------------------------------------
 
     // Returns a value such as "en-US".
     virtual WebString defaultLocale() { return WebString(); }
 
     // Wall clock time in seconds since the epoch.
     virtual double currentTime() { return 0; }
@@ skipping 239 matching lines @@
 
     virtual WebNavigatorConnectProvider* navigatorConnectProvider() { return 0; }
 
 protected:
     virtual ~Platform() { }
 };
 
 } // namespace blink
 
 #endif