Track constant InputDeviceCapabilities objects per-window.

third_party/WebKit/Source/core/events/UIEvent.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.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */
 
 #include "core/events/UIEvent.h"
 
+#include "core/input/InputDeviceCapabilities.h"
+
 namespace blink {
 
 UIEvent::UIEvent() : m_detail(0), m_sourceCapabilities(nullptr) {}
 
 UIEvent::UIEvent(const AtomicString& eventType,
                  bool canBubbleArg,
                  bool cancelableArg,
                  ComposedMode composedMode,
                  TimeTicks platformTimeStamp,
                  AbstractView* viewArg,
@@ skipping 14 matching lines @@
       m_detail(initializer.detail()),
       m_sourceCapabilities(initializer.sourceCapabilities()) {}
 
 UIEvent::~UIEvent() {}
 
 void UIEvent::initUIEvent(const AtomicString& typeArg,
                           bool canBubbleArg,
                           bool cancelableArg,
                           AbstractView* viewArg,
                           int detailArg) {
   initUIEventInternal(typeArg, canBubbleArg, cancelableArg, nullptr, viewArg,

[sof, 2017/02/07 07:41:44]

Ah, all init*Event() get a null |sourceCapabilities|.

                       detailArg, nullptr);
 }
 
 void UIEvent::initUIEventInternal(
     const AtomicString& typeArg,
     bool canBubbleArg,
     bool cancelableArg,
     EventTarget* relatedTarget,
     AbstractView* viewArg,
     int detailArg,
@@ skipping 20 matching lines @@
   return 0;
 }
 
 DEFINE_TRACE(UIEvent) {
   visitor->trace(m_view);
   visitor->trace(m_sourceCapabilities);
   Event::trace(visitor);
 }
 
 }  // namespace blink