Removed |which| from KeyboardEvent and MouseEvent.

third_party/WebKit/Source/core/events/MouseEvent.cpp

 /*
  * 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, 2005, 2006, 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 378 matching lines @@
   if (button_ == -1 || event_name == EventTypeNames::mousemove ||
       event_name == EventTypeNames::mouseleave ||
       event_name == EventTypeNames::mouseenter ||
       event_name == EventTypeNames::mouseover ||
       event_name == EventTypeNames::mouseout) {
     return 0;
   }
   return button_;
 }
 
-int MouseEvent::which() const {
+unsigned MouseEvent::which() const {
   // For the DOM, the return values for left, middle and right mouse buttons are
   // 0, 1, 2, respectively.
   // For the Netscape "which" property, the return values for left, middle and
   // right mouse buttons are 1, 2, 3, respectively.
   // So we must add 1.
-  return button_ + 1;
+  return (unsigned)(button_ + 1);
 }
 
 Node* MouseEvent::toElement() const {
   // MSIE extension - "the object toward which the user is moving the mouse
   // pointer"
   if (type() == EventTypeNames::mouseout ||
       type() == EventTypeNames::mouseleave)
     return relatedTarget() ? relatedTarget()->ToNode() : nullptr;
 
   return target() ? target()->ToNode() : nullptr;
@@ skipping 182 matching lines @@
 
 int MouseEvent::offsetY() {
   if (!HasPosition())
     return 0;
   if (!has_cached_relative_position_)
     ComputeRelativePosition();
   return std::round(offset_location_.Y());
 }
 
 }  // namespace blink