Add machinery to show touch editing context menus in OOPIFs.

third_party/WebKit/public/web/WebWidget.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 206 matching lines @@
                                           WebBrowserControlsState current,
                                           bool animate) {}
 
   // Populate |bounds| with the composition character bounds for the ongoing
   // composition. Returns false if there is no focused input or any ongoing
   // composition.
   virtual bool GetCompositionCharacterBounds(WebVector<WebRect>& bounds) {
     return false;
   }
 
+  // Called by client to request showing the context menu.
+  virtual void ShowContextMenu() {}
+
  protected:
   ~WebWidget() {}
 };
 
 }  // namespace blink
 
 #endif