Remove the SVG update hack.

third_party/WebKit/Source/core/dom/Document.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
@@ skipping 1004 matching lines @@
     void registerVisibilityObserver(DocumentVisibilityObserver*);
     void unregisterVisibilityObserver(DocumentVisibilityObserver*);
 
     void updateStyleInvalidationIfNeeded();
 
     bool attemptedToDetermineEncodingFromContentSniffing() const;
     bool encodingWasDetectedFromContentSniffing() const;
 
     DECLARE_VIRTUAL_TRACE();
 
-    bool hasSVGFilterElementsRequiringLayerUpdate() const { return m_layerUpdateSVGFilterElements.size(); }
     void didRecalculateStyleForElement() { ++m_styleRecalcElementCounter; }
 
     AtomicString convertLocalName(const AtomicString&);
 
     void platformColorsChanged();
 
     DOMTimerCoordinator* timers() final;
 
     v8::Local<v8::Object> wrap(v8::Isolate*, v8::Local<v8::Object> creationContext) override;
     v8::Local<v8::Object> associateWithWrapper(v8::Isolate*, const WrapperTypeInfo*, v8::Local<v8::Object> wrapper) override WARN_UNUSED_RETURN;
@@ skipping 413 matching lines @@
 DEFINE_TYPE_CASTS(TreeScope, Document, document, true, true);
 
 } // namespace blink
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 CORE_EXPORT void showLiveDocumentInstances();
 #endif
 
 #endif // Document_h