[SPv2] Associate effect property nodes for SVG paint chunks

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

Index: third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.cpp
diff --git a/third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.cpp b/third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.cpp
index d6842c36767e7f3e29447ce388f2d69f520308a7..1bccbd2e8b91ef7ac89bac0beeec33e3aafdd03b 100644
--- a/third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.cpp
+++ b/third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.cpp
@@ -10,6 +10,7 @@
 #include "core/layout/LayoutInline.h"
 #include "core/layout/LayoutView.h"
 #include "core/layout/svg/LayoutSVGRoot.h"
+#include "core/layout/svg/SVGLayoutSupport.h"
 #include "core/paint/FindPropertiesNeedingUpdate.h"
 #include "core/paint/ObjectPaintProperties.h"
 #include "core/paint/PaintLayer.h"
@@ -368,10 +369,13 @@ void PaintPropertyTreeBuilder::updateEffect(
     PaintPropertyTreeBuilderContext& context) {
   const ComputedStyle& style = object.styleRef();
 
-  // TODO(crbug.com/673500): style.isStackingContext() is only meaningful for
-  // HTML elements. What we really want to ask is whether the element starts
-  // an isolated group, and SVGs use a different rule.
-  if (!style.isStackingContext()) {
+  const bool isIsolatedGroup =
+      (object.isSVG() && !object.isSVGRoot())
+          ? SVGLayoutSupport::willIsolateBlendingDescendantsForObject(&object)
+          : (object.isBoxModelObject() && style.isStackingContext());
+  const bool isSVGGraphicsElement =

[chrishtr, 2016/12/15 19:21:23]

Why skip SVG graphics elements?

[trchen, 2016/12/15 23:49:46]

It is to include SVG graphics elements.
SVGLayoutSupport::willIsolateBlendingDescendantsForObject() exclude them because
they can't have descendants.

But anyhow, I found this condition is still not quite right. The new patchset
fixed existing tests. (Hope it now matches the existing behavior... It does not
100% adhere to the spec and I have to reverse engineer it.)

+      object.isSVGShape() || object.isSVGImage() || object.isSVGText();
+  if (!isIsolatedGroup && !isSVGGraphicsElement) {
     if (object.needsPaintPropertyUpdate() || context.forceSubtreeUpdate) {
       if (auto* properties = object.getMutableForPainting().paintProperties())
         context.forceSubtreeUpdate |= properties->clearEffect();