Add chromestatus link to a warning

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

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  *           (C) 2007, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ skipping 252 matching lines @@
     }
   } else {
     if (!options.hasPassive())
       options.setPassive(false);
   }
 
   if (!options.passive()) {
     String message_text = String::Format(
         "Added non-passive event listener to a scroll-blocking '%s' event. "
         "Consider marking event handler as 'passive' to make the page more "
-        "responsive.",
+        "responsive. See "
+        "https://www.chromestatus.com/feature/5745543795965952",
         event_type.GetString().Utf8().data());
 
     PerformanceMonitor::ReportGenericViolation(
         GetExecutionContext(), PerformanceMonitor::kDiscouragedAPIUse,
         message_text, 0, nullptr);
   }
 }
 
 bool EventTarget::addEventListener(const AtomicString& event_type,
                                    EventListener* listener,
@@ skipping 527 matching lines @@
   // they have one less listener to invoke.
   if (d->firing_event_iterators) {
     for (const auto& iterator : *d->firing_event_iterators) {
       iterator.iterator = 0;
       iterator.end = 0;
     }
   }
 }
 
 }  // namespace blink