Make first TouchStart and first TouchMove events on a flinging layer non-blocking

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 63 matching lines @@
     , 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_preventDefaultCalledOnUncancelableEvent(false)
     , m_eventPhase(0)
     , m_currentTarget(nullptr)
     , m_platformTimeStamp(platformTimeStamp)
 {
 }
 
 Event::Event(const AtomicString& eventType, const EventInit& initializer)
     : Event(eventType, initializer.bubbles(), initializer.cancelable(), initializer.composed() ? ComposedMode::Composed : ComposedMode::Scoped, monotonicallyIncreasingTime())
 {
 }
@@ skipping 15 matching lines @@
 void Event::initEvent(const AtomicString& eventTypeArg, bool canBubbleArg, bool cancelableArg, EventTarget* relatedTarget)
 {
     if (isBeingDispatched())
         return;
 
     m_wasInitialized = true;
     m_propagationStopped = false;
     m_immediatePropagationStopped = false;
     m_defaultPrevented = false;
     m_isTrusted = false;
+    m_preventDefaultCalledOnUncancelableEvent = false;
 
     m_type = eventTypeArg;
     m_canBubble = canBubbleArg;
     m_cancelable = cancelableArg;
 }
 
 bool Event::legacyReturnValue(ExecutionContext* executionContext) const
 {
     bool returnValue = !defaultPrevented();
     if (returnValue)
@@ skipping 97 matching lines @@
     if (m_handlingPassive) {
         m_preventDefaultCalledDuringPassive = true;
         const LocalDOMWindow* window = m_eventPath ? m_eventPath->windowEventContext().window() : 0;
         if (window)
             window->printErrorMessage("Unable to preventDefault inside passive event listener invocation.");
         return;
     }
 
     if (m_cancelable)
         m_defaultPrevented = true;
+    else
+        m_preventDefaultCalledOnUncancelableEvent = true;
 }
 
 void Event::setTarget(EventTarget* target)
 {
     if (m_target == target)
         return;
 
     m_target = target;
     if (m_target)
         receivedTarget();
@@ skipping 101 matching lines @@
 
 DEFINE_TRACE(Event)
 {
     visitor->trace(m_currentTarget);
     visitor->trace(m_target);
     visitor->trace(m_underlyingEvent);
     visitor->trace(m_eventPath);
 }
 
 } // namespace blink