Re-implement SVG transform paint property nodes [spv2]

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

Index: third_party/WebKit/Source/core/paint/SVGRootPainter.cpp
diff --git a/third_party/WebKit/Source/core/paint/SVGRootPainter.cpp b/third_party/WebKit/Source/core/paint/SVGRootPainter.cpp
index 1cbdbbf6a63e995fa5c18f7810f49941055bbe8a..28894f16e3505803a1ab13fd3bc8a54f21c8d190 100644
--- a/third_party/WebKit/Source/core/paint/SVGRootPainter.cpp
+++ b/third_party/WebKit/Source/core/paint/SVGRootPainter.cpp
@@ -45,24 +45,16 @@ void SVGRootPainter::paint(const PaintInfo& paintInfo, const LayoutPoint& paintO
 
     PaintInfo paintInfoBeforeFiltering(paintInfo);
 
-    Optional<ScopedPaintChunkProperties> transformPropertyScope;
+    Optional<ScopedPaintChunkProperties> propertyScope;
     if (RuntimeEnabledFeatures::slimmingPaintV2Enabled()) {
         const auto* objectProperties = m_layoutSVGRoot.objectPaintProperties();
-        if (objectProperties && objectProperties->svgLocalTransform()) {
+        // If a transform exists, we can rely on a layer existing to apply it.
+        DCHECK(!objectProperties || !objectProperties->transform() || m_layoutSVGRoot.hasLayer());

[jbroman, 2016/06/10 18:33:52]

To be clear, "layer" here is blink::PaintLayer, right?

[pdr., 2016/06/10 19:45:46]

Yeah. I updated the comment to specify "paint layer" so this is more clear.

+        if (objectProperties && objectProperties->svgLocalToBorderBoxTransform()) {
             auto& paintController = paintInfoBeforeFiltering.context.getPaintController();
             PaintChunkProperties properties(paintController.currentPaintChunkProperties());
-            properties.transform = objectProperties->svgLocalTransform();
-            transformPropertyScope.emplace(paintController, properties);
-        } else if (objectProperties && objectProperties->paintOffsetTranslation() && !m_layoutSVGRoot.hasLayer()) {
-            // TODO(pdr): Always create an svgLocalTransform and remove this paint offset quirk.
-            // At the HTML->SVG boundary, SVGRoot will have a paint offset transform
-            // paint property but may not have a PaintLayer, so we need to update the
-            // paint properties here since they will not be updated by PaintLayer
-            // (See: PaintPropertyTreeBuilder::createPaintOffsetTranslationIfNeeded).
-            auto& paintController = paintInfoBeforeFiltering.context.getPaintController();
-            PaintChunkProperties properties(paintController.currentPaintChunkProperties());
-            properties.transform = objectProperties->paintOffsetTranslation();
-            transformPropertyScope.emplace(paintController, properties);
+            properties.transform = objectProperties->svgLocalToBorderBoxTransform();
+            propertyScope.emplace(paintController, properties);
         }
     }