Move dispatchBeforeUnloadEvent to WebFrame, part 1/3.

public/web/WebFrame.h

 /*
  * Copyright (C) 2009 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 223 matching lines @@
     virtual WebFrame* findChildByExpression(const WebString& xpath) const = 0;
 
 
     // Content ------------------------------------------------------------
 
     virtual WebDocument document() const = 0;
 
     virtual WebPerformance performance() const = 0;
 
 
+    // Closing -------------------------------------------------------------
+
+    // Runs beforeunload handlers for this frame, returning false if a
+    // handler suppressed unloading.
+    virtual bool dispatchBeforeUnloadEvent() = 0;
+
+
     // Scripting ----------------------------------------------------------
 
     // Returns a NPObject corresponding to this frame's DOMWindow.
     virtual NPObject* windowObject() const = 0;
 
     // Binds a NPObject as a property of this frame's DOMWindow.
     virtual void bindToWindowObject(const WebString& name, NPObject*) = 0;
     virtual void bindToWindowObject(
         const WebString& name, NPObject*, void*) = 0;
 
@@ skipping 413 matching lines @@
     // text form. This is used only by layout tests.
     virtual WebString layerTreeAsText(bool showDebugInfo = false) const = 0;
 
 protected:
     ~WebFrame() { }
 };
 
 } // namespace blink
 
 #endif