Avoid firing load events on style elements if there is no listeners for that

third_party/WebKit/Source/core/dom/Document.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All
  * rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved.
  * (http://www.torchmobile.com/)
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
@@ skipping 773 matching lines @@
     DOMSUBTREEMODIFIED_LISTENER = 1,
     DOMNODEINSERTED_LISTENER = 1 << 1,
     DOMNODEREMOVED_LISTENER = 1 << 2,
     DOMNODEREMOVEDFROMDOCUMENT_LISTENER = 1 << 3,
     DOMNODEINSERTEDINTODOCUMENT_LISTENER = 1 << 4,
     DOMCHARACTERDATAMODIFIED_LISTENER = 1 << 5,
     ANIMATIONEND_LISTENER = 1 << 6,
     ANIMATIONSTART_LISTENER = 1 << 7,
     ANIMATIONITERATION_LISTENER = 1 << 8,
     TRANSITIONEND_LISTENER = 1 << 9,
-    SCROLL_LISTENER = 1 << 10
-    // 5 bits remaining
+    SCROLL_LISTENER = 1 << 10,
+    LOAD_LISTENER_AT_CAPTURE_PHASE_OR_AT_STYLE_ELEMENT = 1 << 11
+    // 4 bits remaining

[tkent, 2017/04/25 01:36:32]

Oh, this enum wasn't renamed to kCamelCase.

[hayato, 2017/04/25 01:40:13]

Ah, I didn't notice it. :) I can rename these in another CL.

   };
 
   bool HasListenerType(ListenerType listener_type) const {
     return (listener_types_ & listener_type);
   }
-  void AddListenerTypeIfNeeded(const AtomicString& event_type);
+  void AddListenerTypeIfNeeded(const AtomicString& event_type, EventTarget&);
 
   bool HasMutationObserversOfType(MutationObserver::MutationType type) const {
     return mutation_observer_types_ & type;
   }
   bool HasMutationObservers() const { return mutation_observer_types_; }
   void AddMutationObserverTypes(MutationObserverOptions types) {
     mutation_observer_types_ |= types;
   }
 
   IntersectionObserverController* GetIntersectionObserverController();
@@ skipping 919 matching lines @@
 DEFINE_TYPE_CASTS(TreeScope, Document, document, true, true);
 
 }  // namespace blink
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 CORE_EXPORT void showLiveDocumentInstances();
 #endif
 
 #endif  // Document_h