Add WebWidgetTestProxy.

third_party/WebKit/public/web/WebFrameWidget.h

 /*
  * Copyright (C) 2014 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 51 matching lines @@
 
     // Sets the base color used for this WebFrameWidget's background. This is in
     // effect the default background color used for pages with no
     // background-color style in effect, or used as the alpha-blended basis for
     // any pages with translucent background-color style. (For pages with opaque
     // background-color style, this property is effectively ignored).
     // Setting this takes effect for the currently loaded page, if any, and
     // persists across subsequent navigations. Defaults to white prior to the
     // first call to this method.
     virtual void setBaseBackgroundColor(WebColor) = 0;
+
+    // Returns the local root of this WebFrameWidget.
+    virtual WebLocalFrame* localRoot() = 0;
+
+    // WebWidget implementation.
+    bool isWebFrameWidget() const final { return true; }
 };
 
 } // namespace blink
 
 #endif