Introduce NavigatorWebDriver interface

third_party/WebKit/Source/core/frame/Navigator.idl

 /*
     Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
 
     This library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Library General Public
     License as published by the Free Software Foundation; either
     version 2 of the License, or (at your option) any later version.
 
     This library is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 19 matching lines @@
     [MeasureAs=NavigatorProductSub] readonly attribute DOMString productSub;
     // https://www.w3.org/Bugs/Public/show_bug.cgi?id=27786
     [MeasureAs=NavigatorVendor] readonly attribute DOMString vendor;
 };
 
 Navigator implements NavigatorConcurrentHardware;
 Navigator implements NavigatorCookies;
 Navigator implements NavigatorID;
 Navigator implements NavigatorLanguage;
 Navigator implements NavigatorOnLine;
+Navigator implements NavigatorWebDriver;