Initialize all MouseEvent members in all constructors

Source/core/events/MouseEvent.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 52 matching lines @@
     return adoptRefWillBeNoop(new MouseEvent(type, canBubble, cancelable, view,
         detail, screenX, screenY, windowX, windowY,
         movementX, movementY,
         ctrlKey, altKey, shiftKey, metaKey, button, buttons, relatedTarget, dataTransfer, isSimulated, syntheticEventType, uiCreateTime));
 }
 
 MouseEvent::MouseEvent()
     : m_button(0)
     , m_buttons(0)
     , m_buttonDown(false)
+    , m_relatedTarget(nullptr)
+    , m_dataTransfer(nullptr)
+    , m_syntheticEventType(PlatformMouseEvent::RealOrIndistinguishable)
 {
 }
 
 MouseEvent::MouseEvent(const AtomicString& eventType, bool canBubble, bool cancelable, PassRefPtrWillBeRawPtr<AbstractView> view,
     int detail, int screenX, int screenY, int windowX, int windowY,
     int movementX, int movementY,
     bool ctrlKey, bool altKey, bool shiftKey, bool metaKey,
     unsigned short button, unsigned short buttons, PassRefPtrWillBeRawPtr<EventTarget> relatedTarget,
     PassRefPtrWillBeRawPtr<DataTransfer> dataTransfer, bool isSimulated, PlatformMouseEvent::SyntheticEventType syntheticEventType,
     double uiCreateTime)
@@ skipping 14 matching lines @@
 MouseEvent::MouseEvent(const AtomicString& eventType, const MouseEventInit& initializer)
     : MouseRelatedEvent(eventType, initializer.bubbles(), initializer.cancelable(), initializer.view(), initializer.detail(), IntPoint(initializer.screenX(), initializer.screenY()),
         IntPoint(0 /* pageX */, 0 /* pageY */),
         IntPoint(0 /* movementX */, 0 /* movementY */),
         initializer.ctrlKey(), initializer.altKey(), initializer.shiftKey(), initializer.metaKey(), false /* isSimulated */)
     , m_button(initializer.button() == (unsigned short)-1 ? 0 : initializer.button())
     , m_buttons(initializer.buttons())
     , m_buttonDown(initializer.button() != (unsigned short)-1)
     , m_relatedTarget(initializer.relatedTarget())
     , m_dataTransfer(nullptr)
+    , m_syntheticEventType(PlatformMouseEvent::RealOrIndistinguishable)
 {
     initCoordinates(IntPoint(initializer.clientX(), initializer.clientY()));
 }
 
 MouseEvent::~MouseEvent()
 {
 }
 
 unsigned short MouseEvent::platformModifiersToButtons(unsigned modifiers)
 {
@@ skipping 169 matching lines @@
         event().button(), relatedTarget, event().buttons());
     if (event().defaultHandled())
         doubleClickEvent->setDefaultHandled();
     EventDispatcher::dispatchEvent(dispatcher.node(), MouseEventDispatchMediator::create(doubleClickEvent));
     if (doubleClickEvent->defaultHandled() || doubleClickEvent->defaultPrevented())
         return false;
     return !swallowEvent;
 }
 
 } // namespace blink