Re-implement SVG transform paint property nodes [spv2]

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

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/paint/SVGRootPainter.h"
 
 #include "core/layout/svg/LayoutSVGRoot.h"
 #include "core/layout/svg/SVGLayoutSupport.h"
 #include "core/paint/BoxPainter.h"
 #include "core/paint/ObjectPaintProperties.h"
@@ skipping 27 matching lines @@
     ASSERT(svg);
     if (svg->hasEmptyViewBox())
         return;
 
     // Don't paint if we don't have kids, except if we have filters we should paint those.
     if (!m_layoutSVGRoot.firstChild() && !SVGLayoutSupport::hasFilterResource(m_layoutSVGRoot))
         return;
 
     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);
         }
     }
 
     // Apply initial viewport clip.
     Optional<ClipRecorder> clipRecorder;
     if (m_layoutSVGRoot.shouldApplyViewportClip()) {
         // TODO(pdr): Clip the paint info cull rect here.
         clipRecorder.emplace(paintInfoBeforeFiltering.context, m_layoutSVGRoot, paintInfoBeforeFiltering.displayItemTypeForClipping(), pixelSnappedIntRect(m_layoutSVGRoot.overflowClipRect(paintOffset)));
     }
 
@@ skipping 14 matching lines @@
     if (paintContext.paintInfo().phase == PaintPhaseForeground && !paintContext.applyClipMaskAndFilterIfNecessary())
         return;
 
     BoxPainter(m_layoutSVGRoot).paint(paintContext.paintInfo(), LayoutPoint());
 
     PaintTiming& timing = PaintTiming::from(m_layoutSVGRoot.node()->document().topDocument());
     timing.markFirstContentfulPaint();
 }
 
 } // namespace blink