Only allow link clicks on single click.

third_party/WebKit/Source/core/html/HTMLAnchorElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Simon Hausmann <hausmann@kde.org>
  * Copyright (C) 2003, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  *           (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *
  * 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
@@ skipping 355 matching lines @@
     }
 }
 
 bool isEnterKeyKeydownEvent(Event* event)
 {
     return event->type() == EventTypeNames::keydown && event->isKeyboardEvent() && toKeyboardEvent(event)->keyIdentifier() == "Enter" && !toKeyboardEvent(event)->repeat();
 }
 
 bool isLinkClick(Event* event)
 {
-    return event->type() == EventTypeNames::click && (!event->isMouseEvent() || toMouseEvent(event)->button() != RightButton);
+    // Allow detail <= 1 so that synthetic clicks work. They have detail == 0.

[Rick Byers, 2016/05/25 17:25:14]

nit: "they may have", right?  Presumably JS should be passing detail:1 to the
MouseEvent constructor.

[dtapuska, 2016/05/25 19:25:47]

Done.

+    return event->type() == EventTypeNames::click && (!event->isMouseEvent() || (toMouseEvent(event)->button() != RightButton && toMouseEvent(event)->detail() <= 1));
 }
 
 bool HTMLAnchorElement::willRespondToMouseClickEvents()
 {
     return isLink() || HTMLElement::willRespondToMouseClickEvents();
 }
 
 bool HTMLAnchorElement::isInteractiveContent() const
 {
     return isLink();
 }
 
 Node::InsertionNotificationRequest HTMLAnchorElement::insertedInto(ContainerNode* insertionPoint)
 {
     InsertionNotificationRequest request = HTMLElement::insertedInto(insertionPoint);
     logAddElementIfIsolatedWorldAndInDocument("a", hrefAttr);
     return request;
 }
 
 } // namespace blink