Cache the result of isScopedInV0 flag in Event object

third_party/WebKit/Source/core/events/Event.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 16 matching lines @@
 #include "core/events/EventTarget.h"
 #include "core/frame/HostsUsingFeatures.h"
 #include "core/frame/UseCounter.h"
 #include "core/svg/SVGElement.h"
 #include "core/timing/DOMWindowPerformance.h"
 #include "core/timing/Performance.h"
 #include "wtf/CurrentTime.h"
 
 namespace blink {
 
+static bool isEventTypeScopedInV0(const AtomicString& eventType)
+{
+    // WebKit never allowed selectstart event to cross the the shadow DOM boundary.
+    // Changing this breaks existing sites.
+    // See https://bugs.webkit.org/show_bug.cgi?id=52195 for details.
+    return eventType == EventTypeNames::abort
+        || eventType == EventTypeNames::change
+        || eventType == EventTypeNames::error
+        || eventType == EventTypeNames::load
+        || eventType == EventTypeNames::reset
+        || eventType == EventTypeNames::resize
+        || eventType == EventTypeNames::scroll
+        || eventType == EventTypeNames::select
+        || eventType == EventTypeNames::selectstart
+        || eventType == EventTypeNames::slotchange;
+}
+
 Event::Event()
     : Event("", false, false)
 {
     m_wasInitialized = false;
 }
 
 Event::Event(const AtomicString& eventType, bool canBubbleArg, bool cancelableArg, double platformTimeStamp)
     : Event(eventType, canBubbleArg, cancelableArg, ComposedMode::Scoped, platformTimeStamp)
 {
 }
 
 Event::Event(const AtomicString& eventType, bool canBubbleArg, bool cancelableArg, ComposedMode composedMode)
     : Event(eventType, canBubbleArg, cancelableArg, composedMode, monotonicallyIncreasingTime())
 {
 }
 
 Event::Event(const AtomicString& eventType, bool canBubbleArg, bool cancelableArg, ComposedMode composedMode, double platformTimeStamp)
     : m_type(eventType)
     , m_canBubble(canBubbleArg)
     , m_cancelable(cancelableArg)
     , m_composed(composedMode == ComposedMode::Composed)
+    , m_isEventTypeScopedInV0(isEventTypeScopedInV0(eventType))
     , m_propagationStopped(false)
     , m_immediatePropagationStopped(false)
     , m_defaultPrevented(false)
     , m_defaultHandled(false)
     , m_cancelBubble(false)
     , m_wasInitialized(true)
     , m_isTrusted(false)
     , m_handlingPassive(false)
     , m_eventPhase(0)
     , m_currentTarget(nullptr)
     , m_createTime(convertSecondsToDOMTimeStamp(currentTime()))
     , m_platformTimeStamp(platformTimeStamp)
 {
 }
 
 Event::Event(const AtomicString& eventType, const EventInit& initializer)
     : Event(eventType, initializer.bubbles(), initializer.cancelable(), initializer.composed() ? ComposedMode::Composed : ComposedMode::Scoped, monotonicallyIncreasingTime())
 {
 }
 
 Event::~Event()
 {
 }
 
 bool Event::isScopedInV0() const
 {
-    // WebKit never allowed selectstart event to cross the the shadow DOM boundary.
-    // Changing this breaks existing sites.
-    // See https://bugs.webkit.org/show_bug.cgi?id=52195 for details.
-    return isTrusted()
-        && (m_type == EventTypeNames::abort
-            || m_type == EventTypeNames::change
-            || m_type == EventTypeNames::error
-            || m_type == EventTypeNames::load
-            || m_type == EventTypeNames::reset
-            || m_type == EventTypeNames::resize
-            || m_type == EventTypeNames::scroll
-            || m_type == EventTypeNames::select
-            || m_type == EventTypeNames::selectstart
-            || m_type == EventTypeNames::slotchange);
+    return isTrusted() && m_isEventTypeScopedInV0;
 }
 
 void Event::initEvent(const AtomicString& eventTypeArg, bool canBubbleArg, bool cancelableArg)
 {
     initEvent(eventTypeArg, canBubbleArg, cancelableArg, nullptr);
 }
 
 void Event::initEvent(const AtomicString& eventTypeArg, bool canBubbleArg, bool cancelableArg, EventTarget* relatedTarget)
 {
     if (isBeingDispatched())
@@ skipping 247 matching lines @@
 
 DEFINE_TRACE(Event)
 {
     visitor->trace(m_currentTarget);
     visitor->trace(m_target);
     visitor->trace(m_underlyingEvent);
     visitor->trace(m_eventPath);
 }
 
 } // namespace blink