compositor-worker: Introduce CompositorProxy::disconnect().

Source/core/dom/ElementRareData.h

 /*
  * Copyright (C) 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2008 David Smith <catfish.man@gmail.com>
  *
  * 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,
@@ skipping 105 matching lines @@
     InputMethodContext& ensureInputMethodContext(HTMLElement* element)
     {
         if (!m_inputMethodContext)
             m_inputMethodContext = InputMethodContext::create(element);
         return *m_inputMethodContext;
     }
 
     bool hasPseudoElements() const;
     void clearPseudoElements();
 
+    uint32_t incrementProxyCount() { return ++m_proxyCount; }
+    uint32_t decrementProxyCount()
+    {
+        ASSERT(m_proxyCount);
+        return --m_proxyCount;
+    }
+    uint32_t proxyCount() const { return m_proxyCount; }
+
     void setCustomElementDefinition(PassRefPtrWillBeRawPtr<CustomElementDefinition> definition) { m_customElementDefinition = definition; }
     CustomElementDefinition* customElementDefinition() const { return m_customElementDefinition.get(); }
 
     WillBeHeapVector<RefPtrWillBeMember<Attr>>& ensureAttrNodeList();
     WillBeHeapVector<RefPtrWillBeMember<Attr>>* attrNodeList() { return m_attrNodeList.get(); }
     void removeAttrNodeList() { m_attrNodeList.clear(); }
 
     DECLARE_TRACE_AFTER_DISPATCH();
 
 private:
     short m_tabindex;
     bool m_tabStop;
+    uint32_t m_proxyCount;

[esprehn, 2015/04/09 05:14:55]

Do you really need 32 bits worth of these? This is huge. There's probably some
free bits in there, use some of those.

[sadrul, 2015/04/09 16:19:33]

Would it make sense to use a short (unsigned?) instead? (NodeRareData has only 2
unused bits, not enough to be useful for this).

[sadrul, 2015/04/09 16:41:09]

Aha! I wasn't looking hard enough. NodeRareData doesn't have enough unused bits,
but ElementRareData does. I have made this change in the latest patchset (and
limited the proxy-count to 10 bits). The size of the ElementRareData does not
need to increase anymore because of this change, and there are still some unused
bits we could use for other purposes (or for proxy-count if we need to).

 
     LayoutSize m_minimumSizeForResizing;
     IntSize m_savedLayerScrollOffset;
 
     OwnPtrWillBeMember<DatasetDOMStringMap> m_dataset;
     OwnPtrWillBeMember<ClassList> m_classList;
     OwnPtrWillBeMember<ElementShadow> m_shadow;
     OwnPtrWillBeMember<NamedNodeMap> m_attributeMap;
     OwnPtrWillBeMember<WillBeHeapVector<RefPtrWillBeMember<Attr>>> m_attrNodeList;
     OwnPtrWillBeMember<InputMethodContext> m_inputMethodContext;
@@ skipping 13 matching lines @@
 
 inline LayoutSize defaultMinimumSizeForResizing()
 {
     return LayoutSize(LayoutUnit::max(), LayoutUnit::max());
 }
 
 inline ElementRareData::ElementRareData(LayoutObject* renderer)
     : NodeRareData(renderer)
     , m_tabindex(0)
     , m_tabStop(true)
+    , m_proxyCount(0)
     , m_minimumSizeForResizing(defaultMinimumSizeForResizing())
 {
     m_isElementRareData = true;
 }
 
 inline ElementRareData::~ElementRareData()
 {
 #if !ENABLE(OILPAN)
     ASSERT(!m_shadow);
 #endif
@@ skipping 56 matching lines @@
     case FIRST_LETTER:
         return m_generatedFirstLetter.get();
     default:
         return 0;
     }
 }
 
 } // namespace
 
 #endif // ElementRareData_h