Populates sourceDevice attribute into KeyboardEvent

Source/core/events/KeyboardEvent.h

 /*
  * Copyright (C) 2001 Peter Kelly (pmk@post.com)
  * Copyright (C) 2001 Tobias Anton (anton@stud.fbi.fh-darmstadt.de)
  * Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  *
  * 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.
@@ skipping 50 matching lines @@
         bool ctrlKey, bool altKey, bool shiftKey, bool metaKey)
     {
         return adoptRefWillBeNoop(new KeyboardEvent(type, canBubble, cancelable, view, keyIdentifier, code, key, location,
         ctrlKey, altKey, shiftKey, metaKey));
     }
 
     virtual ~KeyboardEvent();
 
     void initKeyboardEvent(ScriptState*, const AtomicString& type, bool canBubble, bool cancelable, AbstractView*,
         const String& keyIdentifier, unsigned location,
-        bool ctrlKey, bool altKey, bool shiftKey, bool metaKey);
+        bool ctrlKey, bool altKey, bool shiftKey, bool metaKey, InputDevice* sourceDevice = nullptr);
 
     const String& keyIdentifier() const { return m_keyIdentifier; }
     const String& code() const { return m_code; }
     const String& key() const { return m_key; }
 
     unsigned location() const { return m_location; }
 
     bool getModifierState(const String& keyIdentifier) const;
 
     const PlatformKeyboardEvent* keyEvent() const { return m_keyEvent.get(); }
@@ skipping 30 matching lines @@
 private:
     explicit KeyboardEventDispatchMediator(PassRefPtrWillBeRawPtr<KeyboardEvent>);
     virtual bool dispatchEvent(EventDispatcher&) const override;
 };
 
 DEFINE_EVENT_TYPE_CASTS(KeyboardEvent);
 
 } // namespace blink
 
 #endif // KeyboardEvent_h