Oilpan: Remove guardRef and guardDeref from TreeScope.

Source/core/svg/animation/SVGSMILElement.cpp

 /*
  * Copyright (C) 2008 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 174 matching lines @@
     , m_cachedRepeatDur(invalidCachedTime)
     , m_cachedRepeatCount(invalidCachedTime)
     , m_cachedMin(invalidCachedTime)
     , m_cachedMax(invalidCachedTime)
 {
     resolveFirstInterval();
 }
 
 SVGSMILElement::~SVGSMILElement()
 {
+#if !ENABLE(OILPAN)
     clearResourceAndEventBaseReferences();
+#endif
     smilEndEventSender().cancelEvent(this);
     smilBeginEventSender().cancelEvent(this);
     smilRepeatEventSender().cancelEvent(this);
     smilRepeatNEventSender().cancelEvent(this);
     clearConditions();
     if (m_timeContainer && m_targetElement && hasValidAttributeName())
         m_timeContainer->unschedule(this, m_targetElement, m_attributeName);

[haraken, 2014/04/24 04:18:43]

I'm a bit confused. In this CL, do we need to remove "all code that touches the
Node hierarchy" from destructors? Or do we just need to remove "all code that
touches TreeScopes" from destructors?

If we need to remove all code that touches the Node hierarchy, we also need to
remove line 204. If no, I wonder why we need to remove line 297 - 304 of
BaseMultipleFieldsDateAndTimeInputType.cpp in this CL.

I understand we're doing the Node transition step by step, and want to
understand what code needs to be removed in this step.

[Mads Ager (chromium), 2014/04/24 10:57:36]

We don't need to change this in this step. m_timeContainer is a RefPtr so
m_timeContainer is still alive. The m_targetElement pointer is only used as a
key in a hash map to remove it with no other access which is safe. We should use
weak processing for this when the timeContainer is moved to the heap, but it is
safe for now.

 }
 
 void SVGSMILElement::clearResourceAndEventBaseReferences()
 {
     document().accessSVGExtensions().removeAllTargetReferencesForElement(this);
 }
 
 void SVGSMILElement::clearConditions()
 {
     disconnectSyncBaseConditions();
@@ skipping 1109 matching lines @@
     if (eventType == "repeatn") {
         unsigned repeatEventCount = m_repeatEventCountList.first();
         m_repeatEventCountList.remove(0);
         dispatchEvent(RepeatEvent::create(eventType, repeatEventCount));
     } else {
         dispatchEvent(Event::create(eventType));
     }
 }
 
 }