Reland of "Tracking reference filter mutation via SVGElementProxy"

third_party/WebKit/Source/modules/canvas2d/CanvasRenderingContext2D.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc.
  * All rights reserved.
  * Copyright (C) 2008, 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2007 Alp Toker <alp@atoker.com>
  * Copyright (C) 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008 Dirk Schulze <krit@webkit.org>
  * Copyright (C) 2010 Torch Mobile (Beijing) Co. Ltd. All rights reserved.
  * Copyright (C) 2012, 2013 Intel Corporation. All rights reserved.
  * Copyright (C) 2013 Adobe Systems Incorporated. All rights reserved.
@@ skipping 203 matching lines @@
     } else {
       // legacy synchronous context restoration.
       reset();
       m_contextLostMode = NotLostContext;
     }
   }
 }
 
 DEFINE_TRACE(CanvasRenderingContext2D) {
   visitor->trace(m_hitRegionManager);
+  visitor->trace(m_filterOperations);
   CanvasRenderingContext::trace(visitor);
   BaseRenderingContext2D::trace(visitor);
   SVGResourceClient::trace(visitor);
 }
 
 void CanvasRenderingContext2D::dispatchContextLostEvent(TimerBase*) {
   if (canvas() && contextLostRestoredEventsEnabled()) {
     Event* event = Event::createCancelable(EventTypeNames::contextlost);
     canvas()->dispatchEvent(event);
     if (event->defaultPrevented()) {
@@ skipping 324 matching lines @@
   }
 }
 
 void CanvasRenderingContext2D::styleDidChange(const ComputedStyle* oldStyle,
                                               const ComputedStyle& newStyle) {
   if (oldStyle && oldStyle->font() == newStyle.font())
     return;
   pruneLocalFontCache(0);
 }
 
-void CanvasRenderingContext2D::filterNeedsInvalidation() {
+TreeScope* CanvasRenderingContext2D::treeScope() {
+  return &canvas()->treeScope();
+}
+
+void CanvasRenderingContext2D::clearFilterReferences() {
+  m_filterOperations.removeClient(this);
+  m_filterOperations.clear();
+}
+
+void CanvasRenderingContext2D::updateFilterReferences(
+    const FilterOperations& filters) {
+  clearFilterReferences();
+  filters.addClient(this);
+  m_filterOperations = filters;
+}
+
+void CanvasRenderingContext2D::resourceContentChanged() {
+  resourceElementChanged();
+}
+
+void CanvasRenderingContext2D::resourceElementChanged() {
+  clearFilterReferences();
   state().clearResolvedFilter();
 }
 
 bool CanvasRenderingContext2D::originClean() const {
   return canvas()->originClean();
 }
 
 void CanvasRenderingContext2D::setOriginTainted() {
   return canvas()->setOriginTainted();
 }
@@ skipping 579 matching lines @@
   }
   return true;
 }
 
 void CanvasRenderingContext2D::resetUsageTracking() {
   UsageCounters newCounters;
   m_usageCounters = newCounters;
 }
 
 }  // namespace blink