Tracking filter mutation via SVGElementProxy

third_party/WebKit/Source/core/paint/PaintLayer.cpp

Index: third_party/WebKit/Source/core/paint/PaintLayer.cpp
diff --git a/third_party/WebKit/Source/core/paint/PaintLayer.cpp b/third_party/WebKit/Source/core/paint/PaintLayer.cpp
index a7ed7bdb3a8a6fcdf93de359267a0189b4915a90..1f002d6f57f81ace6c595f2fa3ff475956d6119d 100644
--- a/third_party/WebKit/Source/core/paint/PaintLayer.cpp
+++ b/third_party/WebKit/Source/core/paint/PaintLayer.cpp
@@ -188,8 +188,10 @@ PaintLayer::PaintLayer(LayoutBoxModelObject* layoutObject)
 }
 
 PaintLayer::~PaintLayer() {
-  if (m_rareData && m_rareData->filterInfo)
+  if (m_rareData && m_rareData->filterInfo) {
+    layoutObject()->styleRef().filter().removeClient(m_rareData->filterInfo);
     m_rareData->filterInfo->clearLayer();
+  }
   if (layoutObject()->frame() && layoutObject()->frame()->page()) {
     if (ScrollingCoordinator* scrollingCoordinator =
             layoutObject()->frame()->page()->scrollingCoordinator())
@@ -2654,7 +2656,8 @@ void PaintLayer::ensureCompositedLayerMapping() {
   m_rareData->compositedLayerMapping->setNeedsGraphicsLayerUpdate(
       GraphicsLayerUpdateSubtree);
 
-  updateOrRemoveFilterEffect();
+  if (PaintLayerFilterInfo* filterInfo = this->filterInfo())
+    filterInfo->invalidateFilterChain();
 }
 
 void PaintLayer::clearCompositedLayerMapping(bool layerBeingDestroyed) {
@@ -2672,8 +2675,11 @@ void PaintLayer::clearCompositedLayerMapping(bool layerBeingDestroyed) {
   if (m_rareData)
     m_rareData->compositedLayerMapping.reset();
 
-  if (!layerBeingDestroyed)
-    updateOrRemoveFilterEffect();
+  if (layerBeingDestroyed)
+    return;
+
+  if (PaintLayerFilterInfo* filterInfo = this->filterInfo())
+    filterInfo->invalidateFilterChain();
 }
 
 void PaintLayer::setGroupedMapping(CompositedLayerMapping* groupedMapping,
@@ -2868,9 +2874,17 @@ void PaintLayer::updateFilters(const ComputedStyle* oldStyle,
   if (!newStyle.hasFilterInducingProperty() &&
       (!oldStyle || !oldStyle->hasFilterInducingProperty()))
     return;
-
-  updateOrRemoveFilterClients();
-  updateOrRemoveFilterEffect();
+  const bool hadFilterInfo = filterInfo();
+  if (newStyle.hasFilterInducingProperty())
+    newStyle.filter().addClient(&ensureFilterInfo());
+  if (hadFilterInfo && oldStyle)
+    oldStyle->filter().removeClient(filterInfo());
+  if (!newStyle.hasFilterInducingProperty()) {
+    removeFilterInfo();
+    return;
+  }
+  if (PaintLayerFilterInfo* filterInfo = this->filterInfo())
+    filterInfo->invalidateFilterChain();
 }
 
 bool PaintLayer::attemptDirectCompositingUpdate(StyleDifference diff,
@@ -3015,6 +3029,13 @@ PaintLayerFilterInfo& PaintLayer::ensureFilterInfo() {
   return *rareData.filterInfo;
 }
 
+void PaintLayer::removeFilterInfo() {
+  if (!m_rareData || !m_rareData->filterInfo)
+    return;
+  m_rareData->filterInfo->clearLayer();
+  m_rareData->filterInfo = nullptr;
+}
+
 void PaintLayer::removeAncestorOverflowLayer(const PaintLayer* removedLayer) {
   // If the current ancestor overflow layer does not match the removed layer
   // the ancestor overflow layer has changed so we can stop searching.
@@ -3037,27 +3058,11 @@ void PaintLayer::removeAncestorOverflowLayer(const PaintLayer* removedLayer) {
   }
 }
 
-void PaintLayer::updateOrRemoveFilterClients() {
-  const auto& filter = layoutObject()->style()->filter();
-  if (filter.isEmpty() && m_rareData && m_rareData->filterInfo) {
-    m_rareData->filterInfo->clearLayer();
-    m_rareData->filterInfo = nullptr;
-  } else if (filter.hasReferenceFilter()) {
-    ensureFilterInfo().updateReferenceFilterClients(filter);
-  } else if (filterInfo()) {
-    filterInfo()->clearFilterReferences();
-  }
-}
-
-FilterEffect* PaintLayer::updateFilterEffect() const {
+FilterEffect* PaintLayer::lastFilterEffect() const {
   // TODO(chrishtr): ensure (and assert) that compositing is clean here.
-
   if (!paintsWithFilters())
     return nullptr;
-
   PaintLayerFilterInfo* filterInfo = this->filterInfo();
-
-  // Should have been added by updateOrRemoveFilterEffect().
   DCHECK(filterInfo);
 
   if (filterInfo->lastEffect())
@@ -3074,16 +3079,12 @@ FilterEffect* PaintLayer::updateFilterEffect() const {
   return filterInfo->lastEffect();
 }
 
-FilterEffect* PaintLayer::lastFilterEffect() const {
-  return updateFilterEffect();
-}
-
 FloatRect PaintLayer::mapRectForFilter(const FloatRect& rect) const {
   if (!hasFilterThatMovesPixels())
     return rect;
 
   // Ensure the filter-chain is refreshed wrt reference filters.
-  updateFilterEffect();
+  lastFilterEffect();

[esprehn, 2016/10/25 01:18:42]

This is strange that it has side effects. Can we refactor it to call whatever
code has the side effects directly instead?

[fs, 2016/10/25 15:00:53]

Sure. That would mean that every time this is called we'd have to redo it
though. lastFilterEffect() has some notion of validity, so it can avoid that.
Note that this is nothing new in this CL though, rather just removing the
indirection.

Another option would be to call mapRect on the FilterEffect returned by
lastFilterEffect().

 
   FilterOperations filterOperations =
       addReflectionToFilterOperations(layoutObject()->styleRef());
@@ -3107,19 +3108,6 @@ bool PaintLayer::hasFilterThatMovesPixels() const {
   return false;
 }
 
-void PaintLayer::updateOrRemoveFilterEffect() {
-  // FilterEffectBuilder is only used to render the filters in software mode,
-  // so we always need to run updateOrRemoveFilterEffect after the composited
-  // mode might have changed for this layer.
-  if (!paintsWithFilters()) {
-    if (PaintLayerFilterInfo* filterInfo = this->filterInfo())
-      filterInfo->setLastEffect(nullptr);
-    return;
-  }
-
-  ensureFilterInfo().setLastEffect(nullptr);
-}
-
 void PaintLayer::filterNeedsPaintInvalidation() {
   {
     DeprecatedScheduleStyleRecalcDuringLayout marker(