Add ExtendSelectionAndDelete handler in WebPlugin

public/web/WebPlugin.h

 /*
  * Copyright (C) 2009, 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 119 matching lines @@
 
     virtual bool executeEditCommand(const WebString& name) { return false; }
     virtual bool executeEditCommand(const WebString& name, const WebString& value) { return false; }
 
     // Sets composition text from input method, and returns true if the
     // composition is set successfully.
     virtual bool setComposition(const WebString& text, const WebVector<WebCompositionUnderline>& underlines, int selectionStart, int selectionEnd) { return false; }
     // Confirms an ongoing composition and returns true if there is an ongoing
     // composition or the text is inserted.
     virtual bool confirmComposition(const WebString& text, WebWidget::ConfirmCompositionBehavior selectionBehavior) { return false; }
+    // Deletes the current selection plus the specified number of characters
+    // before and after the selection or caret.
+    virtual void extendSelectionAndDelete(int before, int after) { }
     // If the given position is over a link, returns the absolute url.
     // Otherwise an empty url is returned.
     virtual WebURL linkAtPosition(const WebPoint& position) const { return WebURL(); }
 
     // Used for zooming of full page plugins.
     virtual void setZoomLevel(double level, bool textOnly) { }
 
     // Find interface.
     // Start a new search.  The plugin should search for a little bit at a time so that it
     // doesn't block the thread in case of a large document.  The results, along with the
@@ skipping 17 matching lines @@
 
     virtual bool isPlaceholder() { return true; }
 
 protected:
     ~WebPlugin() { }
 };
 
 } // namespace blink
 
 #endif